overcharging and blaming the client

Last month telkom double billed my account and took 2 installments off my debit account, took them nearly 3 weeks to refund me. Thinking everything was ok and that they took this month's off my debit account.then late on 13 may 2015 get an sms stating that my account was in arrears and that my contract would be suspended in 48 hrs if I didn't pay. So yesterday I banked their money in at 13:03 to wake up at 3:37 this morning with an sms stating my phones have been suspended. While phoning the call centre this morning, which I recorded, was told it's not my fault it was theirs yet I've still got no working phone. What absolute nonsense. They now rank quite low on customer service.