PROBLEM WITH MY SIM SWAP FOR CONTRACT

I am on CONTRACT and I need to have a sim swap because i was ****** so I called to blacklist the fone and close my sim card than on the same day I bought a new sim card to do a sim swap now problem is that they are failing to help with that today is day two nd m still having the same problem they are telling me about tomorrow nd I need to have that sim card asap because I use it for everything

This is really bad service no one is giving me a clear answer