I need my Cell C number back!!

Hi I bought a Cell C sim card and i wanted to port back to Cell C. Followed all the necessary steps and received confirmation of porting process. Then 2 minutes later I receive this SMS "Sorry, your current operator has declined your port. Dial ********** 287 for further assistance. (Decline ref no. ********** ********** CELLC ********** ********** 2). Can FNB or Cell C explain to me why was my request declined because i can't use this FNB connect cause I don't have an FNB account to recharge and the SIM was given to me as a gift with the FNB phone which i am not us8ng anymore because it was giving me problems. I want my cell c number Back.