No service at all

I received a free LTE sim card from MTN, which I did not ask for or want in the first the place. So I never activated the new sim card. I received messages every day from MTN telling me I haven't started using my new sim card yet, as if I wouldn't know that!!! And in these messages they urged me to swap to LTE. So eventually I decided to swap sim cards. I followed the instructions to the T, and then I received a message that said it is an invalid code. I used the code on my new sim card, as per instructions on the letter I received with the sim card. I tried contacting customer care enquiries, without success. At the start of the call you are told that they are experiencing high call volumes, which I don't have a problem with, but the moment you select the option to speak to a consultant, they drop the call, they don't even give you the option to hold for the next available consultant. So MTN, you can stick your stupid free LTE sim card, and stop sending me messages to start using my new sim card!!!