Last year, Singtel replied to several Forum letters that third-party charges undergo multi-step verification and confirmation processes ("Third-party charges: Singtel replies"; July 7, 2015).

However, this was not my experience. It seems third-party charges for mystery services continue to plague customers.

In December and January, I was billed a total of $96 for downloads.

To this day, I have no idea what it was I allegedly purchased, and I certainly did not give any approval or confirmation for it. I am also the only one with access to my phone.

I reached out to Singtel's representatives on three separate occasions to reverse these unauthorised charges, only to be told that these charges were not Singtel's problem. They were also not able to provide any evidence that I had approved these charges.

Singtel's response has been disappointing.

I believe that I have been a victim of a practice known as "cramming", where unscrupulous third parties sneak fraudulent charges onto cellphone bills.

I hope Singtel takes responsibility for its billing system security rather than blame customers for lapses.

Ho Chi Wei