Shocking Telkom overcharge

In November 2017 I had an ADSL line transfered from Grahamstown to East London as my son had completed his studies at Rhodes. A couple of months later I noticed that I was now being charged for 2 ADSL lines. I went into Telkom Hemmingways and was told that there were in fact 2 accounts and the other was in credit and that the credit would be transfered. This was done, but the credit was actually from an account that I had overpaid and not a 2nd account relating to this ADSL line. My 2nd and 3rd and 4th visits eventually resulted in a R300 credit being passed although the overcharge was over R2000. At least the duplication was stopped. I hoped that the 5th visit would rectify the situation, but alas the line has now been disconnected because I owe R1600 while waiting for a credit of more than this