CELL C DISSAPOINTING ONCE AGAIN

I have 3 contracts with Cell C, and with the upgrades,the kids and I sometimes swop phones around. I did an upgrade for my son and as he already had a small sim, he continued with his old one. I inherited the old phone and opted to use the sim supp**** with it, however Cell C cannot put my number on it. what ****!! The upgrade comes with a sim swap, so what if it is a different number??? as long as they can see that it is one of the numbers on my contracts surely? they did this for me before, now they want to charge. Really Cell C, your service levels are really dropping!!