MtNSA have violated my rights as a customer and must pay for their *** service

I was offered a migration on my MtNSA contract which I accepted telephonically on January 8 2020. Since then MtNSA have not honored their part of this deal as they have been incorrectly billing me and also have changed the contact without my permission back to the original deal prior to me accepting the migration. This is *****. I've spoken to Siphumezo who got it right for a month only for it to change again to the original deal that I had migrated from. Now Frank Phiri tried to assist but this morning informed me that I should read my contract and look for something that stands out related to the migration. Why should I when MtNSA has a telephonic conversation of me accepting the migration. This is *** and I'm very upset. **************** I say. I want my voice heard and my migration reinstated as I as the customer have a right to what I have chosen. How can you keep changing my contract without consent. Sies