BAD MTN MOMO service

MTN MOMO agent gave me the worst experience today, I called regarding changing my MTN linked Momo number to a new number and after calling the MTN the agent advise that I need to go the branch with my ID and when I get to Gateway MTN I am told that they don't deal with Momo and the customer service champion when asked where to go they say they don't have a clue I must check all MTNs to find a store that ha an agent. The security questions as well are not practical all considering I stopped using Momo 3 years I am asked what was my balance when I stopped who would remember that honestly.