Tietong my long-distance calling card is valid approaching, there is still more than 70 yuan calls on the inside, how can we extend the card?Thank you, very urgent!

• 摘要:我的铁通长途电话卡快到有效期了,还有70多元话费在里面,怎么才能把卡的有效期延长?谢谢,非常急!