Phones 4u says it will fulfill any existing mobile contracts, but it's unclear how the company will handle pre-orders of devices made over the weekend

The news that UK phone retailer Phones 4u has gone into administration has left existing customers and those who pre-ordered mobiles including the iPhone 6 in confusion.

The retail chain, which closed 550 stores this Monday after mobile operators EE and Vodafone cancelled contracts, has assured current customers that their contracts will be fulfilled - but individuals who pre-ordered devices will be less fortunate.

"Any orders that have not already been dispatched will be cancelled and any payments refunded to customers," said the company in a statement given to The Independent. "We apologise to our customers for the inconvenience."

The Phones 4u website (which offers an apology from “the heartbroken Phones4u Team”) lists several numbers to call including the company’s customer service line (0844 8712253).

The closure of the chain, which is due to mobile operators’ ambitions to sell directly to consumers, will also affected Dialaphone customers, which was acquired by Phones 4u in 2008.

"Today is a very sad day for our customers and our staff," said Phones 4u chief executive David Kassler in a statement. "If the mobile network operators decline to supply us, we do not have a business. "A good company making profits of over £100 million, employing thousands of decent people has been forced into administration."