CONTRACT DEBIT ORDER

I have a huge problem with the service provider of MTN, I took and iPhone 11 under a 3rd party Incredible Connection through MTN in 2023 April… I started by paying R529 but each and every month it goes up ridiculously when i call them I do not get actual response, let alone the annual increases but the are times where they debit twice in a month my money.. I am tired of calling and what us worse I do not even use their Sim card