Consumers should have the right to use the balance of their prepaid phone cards after the cards expire, the Beijing Consumers' Association said on Thursday.

During the past five years, the association has received many complaints about prepaid phone cards.

"It is not right that some telecom companies don't return the balance after the cards expire," said Qu Jianhui, general secretary of the association.

"Because consumers have already paid for the service in advance, they should still have the right to manage it, even if they don't use all."

China Mobile said consumers can text YCYXQ to 10086, its customer service number, to extend the expiry date for three months.

But Qu said this problem has nothing to do with how long consumers can extend the expiry.

"It is against labor law and the law protecting consumer rights and interests."

Xu Yingchang, a resident of Tongzhou district, said it is not fair she can't use all the money on a card. "The average cost of my phone bill is only 10 yuan a month and a prepaid phone card of China Mobile expires in 90 days," Xu said.

"I have to continue to buy cards just to keep my mobile phone working."

Qu Xiaodong, an expert in the IT industry, said the fixed expiry date violates the benefits and rights of customers who pay for services in advance.

He blamed the fact that the telecom industry is controlled by only a few companies that set the rules.

"If the telecom industry becomes an open market, I'm sure the situation will be much better," Qu said.