When Singapore Post customer Janan Loh ordered a pair of Bluetooth earphones online earlier this year, he waited eagerly for a few days for them to arrive from the United States.

That wait stretched into weeks and became such an exercise in frustration that he set up a Facebook group rallying others who had been similarly affected.

The 35-year-old chief operating officer at a social enterprise eventually got his $238 earphones when he told the company, Jaybird, that he had never received them, and it sent him another pair without additional payment. It was more than a month after his first order.

This time, the company sent the item through courier company FedEx. The first pair never showed up and all he got from calling SingPost's customer care hotline was frustration, he said.

"When they called me, they would give excuses and ask me to wait a few more days. And they would throw me around to different representatives," said Mr Loh, who noted the call centre was based overseas, and he could not get to someone in Singapore till several calls later.

Another customer, a financial consultant who wanted to be known only as Shirley, 25, had a similar experience with a $200 mobile phone she ordered directly from Chinese electronics company Xiaomi in January.

Two months went by and she did not have her phone. When she told the company, it sent another set, but she never got the first.

When an item to or from overseas cannot be found or is not delivered, what SingPost can do is "raise a request" and start an investigation, said Ms Lily Loo, SingPost head of group customer service.

Sometimes mail, whether from overseas or sent locally, does not reach recipients because the sender did not clearly indicate the address. In some cases, the packaging has been damaged when it arrives in Singapore, and the recipient's address cannot be made out.

Such items are held for three months and when customers approach SingPost about missing mail, staff will first check to see if their package is among them.

Beyond this, however, the odds of tracking down a package are small.

SingPost said parcels from overseas, no matter the kind of postal service used and whether the parcel is registered or not, are handled as basic mail and cannot be tracked. "Technically, we can't even declare something is 'lost' because we cannot be certain if the item is indeed in our system," said Ms Loo.

Even though registered articles from overseas come with a tracking number, scanning the items to determine where they are may not be required at every stage, so it can be difficult to pinpoint the items' exact location, Ms Loo added.

The same happens for items posted overseas from Singapore.

While SingPost does not track basic mail, the ratio of lost registered articles is one to 500,000.

SingPost receives 60,000 to 70,000 packages a day, an increase of 40 per cent from five years ago, said Mr Tan Tien Po, the firm's senior vice-president for domestic mail. Of these, about 15 to 20 per cent are from overseas.

SingPost has also increased the number of postmen over the past two years by 15 per cent to about 700 to meet higher package delivery demands. Some are hired from Malaysia and China. Over the same period, bigger vehicles have also been bought, to increase the load of mail that can be carried.

Mr Tan said it also bought an additional package-sorting machine two years ago that sorts packages automatically to the different areas they are mailed to. It is also exploring various kinds of technology to improve deliveries to people's doorsteps and give customers better updates.

On their part, senders should write complete addresses and provide their details should the packages be undelivered, he said. Packaging should also be appropriate so it does not tear.

During a visit to the SingPost mail processing facility in Paya Lebar last month, The Straits Times saw wedding cards without addresses, and packaging with rubber bands that cannot be put through sorting machines.

At a unit for items that could not be delivered because they had fallen out of their packaging or had incomplete addresses were a pair of Timberland boots, a pair of Adidas sneakers, a ring in a box, and various small items.

Letters to God and Santa Claus were also among them.

While SingPost did not reveal the number of complaints it gets, it said that it receives complaints, feedback and queries across its various services, from postal to courier services, and deals with an average of seven cases every 10 days.

Another common complaint was that customers could not understand the speech of customer care officers in India, and vice versa, but Ms Loo said there are stringent quality checks, and they do request customer care officers who can communicate effectively.

She added that SingPost works only with call centres that are ranked the highest.

In total, it delivers some three million items a day.

She said: "Things will go wrong. We are here to fix it. Service recovery is very important, and we make regular improvements."