poor bad service

I bought a phone in June at Ackermans Newcastle mall (CastleRock) in September i experienced some problems with the phone as it was not coming on nor charging i took it to Ladysmith Mall ackermans and the lady and the guy there took it to back and come back and said i should take it back to where i bought it,i called the callcentre and asked if this was true they said no because for a warranty you can take it to any shop unless it is a guarantee so i took the phone to the other ackermans at the square in ladysmith they took the phone and send it for repairs but mtn refused to repair the phone and said my phone was opened which i never did and that they will send proof but never did until today...but overall service at ackermans is very bad they do not do follow ups you have to call the provider yourself and do follow up