Account handed over for no reason

In March I signed up for a Telkom mobile contract filled out a form at Stanger TDS with correct banking details. In June I was notified via sms that my account was to be suspended and when I followed up with 081180 I was told that a debit order had gone through and there were no funds in my account. The debit order was sent to my previous bank for reasons I don't know because when I app**** for the contract I provided updated banking details. I paid R300.00 from the R245 that was in arrears and provided the correct banking details once again. The debit order was to off last day of June and again in July no debit order was sent through. And now when I call to find out why my account is not being debited I am being told my account is arrears and have been handed over to collection. Why would my account be sent to collection when I have provided the correct banking details and yet you are not debiting the account and you can cannot tell me why its in collection. The consultant even confirmed the information of the banking details that they have and it is correct but she cant say why my account is behind and why its in collection.