extremely bad service from MTN Cresta mall,dont buy or take any contract with them

I took a contract 2018 with MTN SA (cresta mall) which had two phones and I was told by the consultant that I will get data and minutes on the main phone and will only get airtime on the other phone .so I did a sim swap on the main phone because I wanted to use the same number I had and the consultant was supposed to give me the sim card for the other phone where ill be getting the airtime but she asked me to come collect the sim card the following day because for some reasons they did not have on that day .so I did go the next day she said they still waiting I kept going back and getting excuses until I was told the consultant went on maternity leave and no one can be able to assist me .so I paid my premiums nicely until I was left with the last premium and I decided I wont pay it till this matter is resolved now all they do is harass me with smses ,calls and email but no one seems to care where im coming from and why i did not pay the amount .i wouldn't refer anyone to them ,bad service indeed :( so i was paying for half a deal