Consumers rights violation - number cancelled due downgrade, forced to upgrade

My mom downgraded her contract and Cell C blocked her number and now they say if she wants to reactivate her number she needs to upgrade her contract. This is totally unacceptable and it daylight robery for them force her to upgrade by cancelling her number just she opted for a downgrade. I am so upset because she feels obliged to because she doesn't want to go through trouble of changing her number and having to update all her personal stuff by getting a number. If this matter is not handled I will escalate it to consumers commission as this is a violation of her rights.