Cell C Changes T & C's on all existing contract unilaterally Without discussion.

We have had 2 x contract with Cell C since 2003. Every two years we upgraded with no issues. (BACKSTORY) In 2010 my husband broke his back in a work related injury, we had to go under Debt review. the contract was paid every month without fail - no exception. All Debts were paid in full in 2012 with the insurance funds but due to Debt Counselor Committing suicide and him going bankrupt, we are unable to get our file. to start over they asking R 20 000 to remove our name from Debt review. We have no debts - except a monthly bill with CELL C - Now 10 years later they are refusing to upgrade as they changed their Rules without informing us that it has changed - and I am unable to upgrade. Should I go to another service provider with the same number.