Highly Dissatisfied MTN Customer

My name is Refiloe ****ubje, I can be reached at ********** 794. I am not happy with the service I got at MTN Southgate the one next to Pick n Pay liquor. I went there on the 10th June 2019 and took a contract phone (iPhone 7), I previously had a contract with MTN with I had paid off so when I got to MTN I wanted to use my old number however I was told that I wont be able to use my number because it is still on their contract list and because it is not an upgrade the consultant Sipho suggested that I take a new sim card. Now my problem is that ever since I have taken this iPhone 7 with the new number I haven't been able to use the internet, in fact the phone displays no service at the top right where it has to show 3G/4G. You can imagine my frustrations I've had this phone for 8 days now and it seems like I am using a demo. Well initially I thought I am still getting used to the phone however after 48hours I decided to take it upon myself and called 808, MTN Contact Centre and I spoke to an advisor who tried to assist me by troubleshooting the iPhone with me over the phone but we failed.. the advisor then informed me that she will escalate this issue and requested for 24hours for the team to resolve the network issue I had on the iPhone. I patiently waited for 72hours and still had no feedback from anyone who works at MTN regarding the iPhone network. I then took it upon myself to go to MTN Southgate on the 15th June 2019 and I was told that the department that deals with sim card connections works Monday to Friday so I should call on Tuesday to get assistance regarding the no network connection on the phone since Monday was a holiday. So today I then called MTN Southgate and spoke to the Manager Kgomotso Matlakala who showed no rumours and said to me it's not her business if my sim card has no network and that Sipho the consultant who assisted me with the contract will call me back. I'm really frustrated, I don't know what to do because MTN has been taking me back and forth regarding this matter and now the same manager Kgomotso Matlakala told me that I will have to pay R115 for a sim swap since my sim card has no network connections. Really I don't know what to do at this point. Please help me because I am stuck with an iPhone that has no network, it's like a demo now. And the sad part of this all is that on the 25th MTN will debit me the amount of R299 for a device I have not even enjoyed and even got to use. Thank you in advance for your assistance.