Contract cancellation from HELL

Hi, I have cancelled my 2 contracts with MTN. The 1st one was supposed to be cancelled effective 22/05/2022 to which it was not. It was changed to a month to month & I am still being charged for it! Which I do not want. I need it cancelled entirely off of my profile. I have made numerous calls to MTN cancellations department & they say that they have cancelled the contract but the person that did it, did not have the authority to do it completely & therefore put it on month to month. Apparently the retentions department can do it. But I have been 'transferred' to this department alot but each time get the voice menu options & no matter what option I choose, I end up back in the cancellations dept. Who cannot help me! I am so frustrated, annoyed & feel helpless because I. Getting charged for something I am not using anymore! Please someone out there can you PLEASE HELP ME OUT.