Not a very happy customer

Hi, all I have an had a cellphone contract with cell c and it was coming to an end in July which I initially requested them to terminate it once it is paid up because I didn't want to upgrade but then they had a special for a router and 40 gig data which I then agreed to take with the sales agent when he called me onow 04/06/2018 who's name is Thabiso Bokgatsu, he explained that the data will be loaded on my sim card in august due to my previous contract being active and I understood and he said in the meantime I can convert my airtime that I receive to date, the router was delivered to me, i then inserted my sim card in the into router but it doesn't register any network signal, I then changed tried 5 sim different cards in the router which works just fine and it doesn't connect to the Internet, I then called the customer center and spoke to some guy which he gave a huge story and told me it the sim card doesn't show any network signal because it had insufficient funds and that he would credit my sim card with R1 for network to connect which I had agreed because I want to use the router, he told me to wait 15 minutes before I can use the sim card which I did and still the very same problem prevailed. Today on the 1st of July I went to cell c shop in greenstone and I spoke to a lady by the name which I explained the whole problem to her she even cheked the router and inserted my contract sim in it and she saw that it doesn't want to register any network signal when it is inserted in the router, she told me she doesn't know what the problem is and she didn't even bother to call head office for assistance, she then told me we can do a sim swap but I will have to pay for it which in store costs R115 and if I do it over the phone costs R50, I theneed told her I don't think it's fair for me to pay for a problem that I did it create, I told her it's cell c's sim card that doesn't want to work in the router why must I carry that cost, she again said she doesn't know what the problem is so when I asked to see the manager she told me the manager is not available, can a well informed person from cell c plz contact me on as I am not happy with the service I'm getting so far from this company, is this a way of them getting extra cash from customers where if their sim cards don't want to function in their devices customers have to pay for that? I am not a very happy customer at the moment as all the pwoke I've spoken to appear to be clueless, if a sim swap will resolve this matter then cell c should not charge me as this is not my fault and if it is not resolved, I will take this to the credit ombudsman and will reverse the payments as their sim card is the problem not me or they should just cancel this whole data contract and take their router back and I'll continue with telkom as they give me any problems