A company has been fined £50,000 for bombarding mobile phone users with unwanted text messages.

Moby Monkey was found to have seriously misled the phone owners with the message, which said they had won its "£500 mystery award".

The prize turned out to be holiday discount vouchers with a variety of conditions attached.

The message gave a premium-rate telephone number and those who dialled it were charged £1.50 a minute for a call lasting three to four minutes.

Eventually they were told the prize was vouchers worth in some cases as little as £150.

The Independent Committee for the Supervision of Standards of Telephone Information Services (Icstis) said it had received more than 200 complaints about the messages. Among them were complaints from parents whose children, in some cases as young as 11, had been targeted.

Other people said they had received the message many times, in one instance up to 40 times in a day.

Icstis said it had fined Leeds-based Moby Monkey and barred the message from being sent.

Director George Kidd said:

"We will not hesitate to take swift action against the small minority of service providers who think they can abuse public confidence and trust in text messaging to make money with no regard for consumers whatsoever.

"Our sanctions against Moby Monkey reflect the serious consumer harm caused by its service and its promotion and will act as a warning to the industry.

Misleading consumers in this way is totally unacceptable.

"Promotions of this kind are likely to be barred immediately and the offending companies fined heavily."

The bad news for Moby Monkey continued.

A message on its site said:

"The company behind this web site has failed to pay for it and other work associated with it, despite a court judgement that they should do so.

"As a consequence, this site has been suspended until payment is received."

The UK premium rate market generated about £600 million revenues last year, according to Icstis, which said there were about 20,000 services in operation at any one time.

In February, telecoms watchdog Oftel introduced new powers to disconnect companies sending rip-off premium rate text messages to mobile phones.

Under the powers, the director general of telecommunications David Edmonds can order the disconnection of the service when the operator ignores a request from Icstis to terminate it.

Mr Edmonds said: "While the vast majority of companies that offer premium rate services are responsible and abide by the industry's code of practice, certain premium rate lines have failed to meet acceptable service standards.

"There have been cases of competition lines where callers run up high bills but never receive their prizes and, more recently, unsolicited premium-rate text messages that promise cash prizes or invitations to join adult chatlines. These new tough powers will enable Oftel to support Icstis' work to stamp out these abuses quickly and protect consumers."

www.oftel.gov.uk