Afrihost and their sim card issues

I had an issue with my router not working, I contacted Afrihost to sort out the problem, they said I must get a new data sim card, because MTN no longer picks up the sim card, so Afrihost asked me buy a new sim card from them which include the courier cost. So when Afrihost has a problem with a sim card I need to purchase a sim card all the time for the problem they have with the network companies, that cannot be my problem the agreement was not get sim cards every now then when I have problem with my data, that unacceptable service.