The Consumer Council warns mobile phone users to check their bills for charges to services they may not have subscribed for, such as ring tones, SMS and MMS.

The council said today it received 470 complaints over disputes on such charges in the first 11 months of this year, with one case involving more than $10,000. In most cases, the complainants did not know the reason for the charges.

Complainants using automatic credit-card transfers for bill payments also questioned telecom companies' passing on of payments on their behalf to other service providers without users' consent.

Complaints of this type have grown from 85 cases in 2006 to 608 last year. The council called on telecom companies to review the situation and stop growing consumer discontent. It suggested operators put aside disputed charges until the matter is resolved with customers, and continue providing normal service to the users until the resolution, without insistence of full payment or termination of service.

Meanwhile, it called on consumers to be wary of unsolicited promotional offers, warned against disclosure of personal data to third parties, and urged continuous checks on phone bills.