Poor service from Telkom

I have a contract with Telkom, I sent an email requesting them to change my debit order payment date. I informed them that my date has changed and I would like to give them my new debit order payment they responded saying that they are dealing with my query. I again requested them to issue me with the banking details and I am still waiting. I personally went to Mahube Mall could not be assisted because there was only 3 people helping us and we stood there for more than an hour. What should I do because I don’t want to have a bad record with Telkom?