porting old number to a new contract

i recently got a new contract deal with Vodacom, due to a miscommunication my need to port my old (Cell C) number was overlooked so i now have a new contract with a new number. i would like to keep my old number as i have used the same number for 10 years and i am not looking to change it. how can this be done?

I have not used this new contract yet, it is still as it was when i signed for it. i dont not what to change anything else, besides the number. i just want to keep my old number.

Please assist