MTN cancelled my BIS in error

On 17 Feb I called MTN with an accounts query , I have beeb overcharged since MTN took over my account from Nashua . I took out a sim only contract in December and am still being charged for a device . I phoned in Jan to rectify and I was promised a refund . This never happened . In Feb I asked again , held on for half an hour , and finally got through to be cut off 3 times!! Then spoke to Lerato Ref *** . She aparantly fixed the problem and at the same time as requested by me , removed the bis from 1 of the numbers on my acc . I asked her to make sure it was removed from *** only and she said it was . After the call I found she han also removed bis from *** which I specifically asked her NOT to do . I cacced again ref *** to reinstate it and I'm still waiting 32 hours later in spite of calling AGAIN today ref *** and being promised a call back from Sepele by the end of business today . I am frustrated disappointed in MTN , and STILL waiting !!!