Telecom has pledged to refund customers hit by a quirk in how its new 3G network is billed.

One launch customer - who quickly relayed his experience on the Geekzone website - bought one gigabyte (GB) of data for $54.95 on May 29.

That’s the standard price for 1GB under Telecom’s “Extras” programme for XT, which allows customers to “bolt-on” a set amount of text or data to their voice plan.

The customer assumed the 1GB of data would apply to the next 30-day billing cycle.

In fact, it applied to the calendar month. A couple of days later, on June 1, his 1GB had expired, and he was automatically switched to the casual XT rate of $1 for 1MB - which equates to $1024 for 1GB.

Other Geekzone members posted comments about similar experiences, which were in turn relayed by Computerworld.

However, the geek rage was calmed after posts by Telecom PR manager Nick Brown, who pledged that affected XT customers would be refunded

Mr Brown told NBR that Telecom would move to a “pro-rata” system for “Extras” in future, but exact details of when the billing tweak will kick-in, or how it will be shaped, have yet to be announced.