Bad customer service

After 16 calls to Customer services, my problem is not solved as yet!! Went to the nearest MTN branch 3x , they phoned 135, no help. I have a business phone. When I tried to change my greeting on the phone, is says: your greeting is enable to review this greeting - so there is no greeting. I need that greeting ASAP! Is it realy so difficult to give service?? -1 rating from me!