Nobody can help to change a month to month contract to prepaid

I have been to the MTN Canal Walk store (Shop 101) 5 times since last year April to transfer the number from company's account to my personal account, even now it is still not resolved. All required document was submitted in September 2018 during my 3rd visit at Canal Walk store, and they scanned and submitted. 1 week later i went to visit same store at Canal Walk and to follow up, they said everything is "finalised" and "solved", and i do start receiving bill from MTN. Last week i went to MTN V&A Waterfront store to change from month to month contract to prepaid but the consultant at V& Waterfront said to me i can't because the account is under the company's name and i need the company letter to do that. This was very upset me because as i understand the account has already transferred to my personal account. The consultant showed me their system and advised that the only thing I have to do is to get a letter from the company. Today i went back to MTN Canal Walk store with company's letter but they said they can't do it. They ask me for more document such as company direct ID copy...I am so frustrated that every time I went to store and got different request from different consultants. After all documents submitted, the problem still can't be resolved. I just want to change my number to prepaid and leave MTN. Someone from MTN please advise how to get it done???