No care attitude

I called mtn today and asked if I could change the banking details and was advised that I could not as they take 30 days before they can change the details on the system. I told the lady Ndileka Nomkonko that this is the worst service provided I have ever been with and I regret leaving cell c cause I never had such issues all she says to me is there anything else I can help u with u could not help me to change the banking details do u really think I need any other help I am going to close this account asap and will tell all my family and friends to change there network as well pathetic service and u have to hold for an hour before u get assistance