Wrong package and wrong charge mtn

I have upgraded my contract on my business name last year with mtn Westwood in Durban. Despite giving them all the details and the type of deal I wanted to upgrade to they still gave me the wrong package. I noticed the difference on billing on my bank statement and queried it with the above franchise. Need less to say they don't know what is customer service and follow up. To cut it short I have been liaising with them since January 2021 and only empty promises were made. I eventually made contact with the owner of the store and she as well promised to sort it out..... It's been 3weeks. Now she ignores my messages and calls. I would advise everyone to be careful when dealing with mtn Westwood or any franchises owned by them. If I do not get the matter Resolved I am going to take a legal opinion by the end of this week