Unacceptable!

I have had a Cell C SIM card for my data usage. Just recently I put 3 gigs on the SIM card. Now I get told that the sim card itself has been blocked. And the number I've been using is no longer mine. I called they told me to get a new Sim, which I did, I then called to get a sim swop which I was then informed couldn't happen because the number that was mine no longer belongs to me. This is ridiculous! I've now lost R300 of data, I'm unable to get my work done because my internet is no longer working! What is going on with the administration in this company.... I'm so disappointed, and they don't have a complaints line that I can speak to anyone. I can only email.... Not pleased