My line number blocked for more than 5 days

I skipped my March 2016 payment for my Cell C Contract with Mondo Mobile and the next thing i new my number was blocked and could not do anything with my phone without any warning . I then called the customer service agent (Trisa)who told me that i have to make the payment before they could unblock my number, They deducted R79 from my account and promised to unlock my number immediately but days later i still can't use my phone. I spoke to Trissa a couple of times and she kept on telling me that she will follow up get back to me, which never did. SO I WANT MY CONTRACT TO BE TERMINATED WITH IMMEDIATE EFFECT AND I WANT MY NUMBER UNLOCKED IMMEDIATELY.