T-Mobile customers stung by phantom call charges

Up to half a million T-Mobile customers have been charged for calls they didn't make thanks to a month-long glitch in the mobile network's billing systems.

Users who called their voicemail service, which should be free, were instead lumbered with call forwarding charges.

T-Mobile identified the problem, which lasted from 31 March to 28 April, and has promised to credit the account of every affected customer. We have to wonder how long it would have taken the company to fess up to the mistake if it weren't for eagle-eyed customers scanning their bills.

The story was broken by consumer site Bitter Wallet. T-Mobile said that "less than 4 per cent" of its customers were affected, but with around 13 million UK users that could mean up to 520,000 people paying over the odds. The average discrepancy was 26p for each call, however, suggesting T-Mobile pocketed hundreds of thousands of pounds.

Taking a peek around the Web, it's remarkably quiet on the subject. Twitter peeps aren't saying much, apart from tech sites covering this story, and T-Mobile UK's Twitter page is silent on the matter. Bloggers are tight-lipped too. A few Bitterwallet readers were affected, but three out of half a million isn't exactly a tidal wave of anger.

We're fairly certain most people just haven't noticed. Even customers who elect to receive a fully itemised paper or online bill aren't religiously checking every call and charge. Had the discrepancy been tens or hundreds of pounds the situation would have been different, but an error of a few pence seems to have slipped by largely unseen.

The other option is that of confusion. Mobile tariffs can be difficult to understand and some customers may simply be getting used to being stung for calls and data falling outside their inclusive allowance. This was a genuine mistake by T-Mobile, but would you instantly be able to tell the difference?