Mobile phone customers have been left phoneless and frustrated after an unexpected surge in demand for pay-as-you-go mobile handsets.
Demand for BT Cellnet's Easylife phone has soared since supermarkets slashed their prices for the pay-as-you-go handset earlier this month.
But customers who have bought the cut price phones have found the 'top-up' lines and customer helplines constantly jammed, leaving them unable to activate or upload minutes to their phones.
Cellnet said it was caught out by the rush and has asked customers to be patient. It has also ramped up its call centre operations to cope with the demand.
Supermarkets Asda, Tesco, Safeways and Sainsbury's earlier this month cut the price of their phones to as little as £39.99. Barclaycard has also offered a free BT Cellnet phone to all card holders.
BT Cellnet Easylife customer Rob Juman Blincoe bought his phone five days ago and is still unable to top up his call time credit. He said: "I am very annoyed. It seemed a fairly straightforward procedure according to the box. You make one simple call to Cellnet at any time, 24 hours a day, seven days a week and you can then use it immediately. Instead I have been unable to get through at all."
One Barclaycard holder said they had to wait two months initially to receive their phone and after two days they were still unable to top up their call time credit.
A spokeswoman for BT Cellnet said: "The demand has been much higher than we expected and we have been activating a huge number of people. This has led to a big time delay in the system, but we are confident this is a short-term problem which is already easing."
The spokeswoman confirmed that Cellnet has increased the number of customer operators by 40 per cent and the number of phone lines by 30 per cent. "It was an unprecedented surge in sales and we hope everyone will be patient."
She added: "Usually we are well prepared for an increase of customers, such as during busy times like Christmas, but the retailers did not forewarn us of their plans to cut prices. We are not happy that so many customers have been unable to use their phones and we are constantly monitoring the system to look at other possibilities."
Cellnet recommends customers call at off-peak hours, after 10pm and into the early hours of the morning. However, customers using the Barclaycard deal must activate their phones during working hours, so must put up with the rush.
Ssupermassive black hole is so big it corresponds to four per cent of the galaxy's total mass
Imminent attack will target a single bank with cloned cards used to fraudulently withdraw millions over one weekend
Using photocatalysts to convert carbon dioxide into usable energy such as methane or ethane
Trained on curated data from Moorfields Eye Hospital, the neural network also shows clinicians how it reached its judgement