Comment Tesco's pile 'em high, sell 'em cheap philosophy works for most things - but not neccessarily telecoms it appears.

A four minute call to a US freephone number, using a Tesco Internet Phone connection, cost one Reg reader £1 a minute - 50 times what it would have cost to dial up a normal US number.

When we contacted Tesco to confirm what the rate should be, it told us it had no idea and no way of finding out.

Tesco Internet Phone is a VoIP offering. Cheap calls are made by computer and routed over the internet for the majority of the connection, then connected using a local (cheap) call. Like most VoIP providers, Tesco provides free calls to other subscribers, and very low cost international calls - two pence a minute for a normal call to the US.

The problem comes with the plethora of billing services now available. Anyone who has called a US freephone number from the UK will be familiar with the recorded announcement informing you that international billing will apply. The same thing happens if you phone a UK freephone number using a mobile telephone. But for this call no warning was received, just a bill for £4.42.

We phoned Tesco Internet Phone at its Crewe call centre. It told us it has a chart of rates, and US freephone numbers aren't on it - therefore, it has no way of knowing how much such a call would cost. We suggested this was patently ridiculous, but were told that no supervisor was available and no further information could be supplied.

Billing tables are increasingly complicated, and mistakes are endemic in the industry. An Informa survey from a few years ago found that every single mobile operator had at least one error in its billing tables.

Tesco shouldn't be pilloried for overcharging, but having a help line that can't advise how much a call is going to cost is the kind of customer service which will send customers back to BT post haste.

Tesco telecoms PR department could not be reached for comment. ®