Number canceled

I have had my Cell C prepaid number for more than 20 years, last week I get an SMS stating 'your cancelation request has been processed and your contract will be terminated on a specified date' so since I don't have a contract with cell c I just ignore the SMS. A few days later my prepaid cell c number stopped working. Today I call the customer services and they inform me that my prepaid number has been canceled and recycled. How do you recycle a number that is still active and without informing your customer. I have used this number for 20 plus years, all my clients all my banking and personal logins I use this number now without warning I don't have that number anymore. As it stands I am losing business because of Cell C. Something must be done ASAP because I want my number back.