Ongoing upgrade nightmare

I have had an account with MTN cerca 1997 & now since 30 March '24 have been trying to perform an upgrade, as at 17 May not been completed!! No phone was sim benefits!! Have dealt with inefficient staff at Irene Mall store and beurocracy at the call centre. Lindile and Cikizwa have tried to assist but application circled authentication (all documents supp**** 3x) credit checks (contract approved and then system got stuck) and so it goes ! If I want to cancel my contract which is within my right since I started the process 30 March and contract ended 16 May, MTN could not renew , I need to pay ~R450!! Furious with MTN