Billed on contract that has ended

I am turning red with anger due to MTN's treatment of their customers!! I had a contract that ended on the 31st of April.I called 30 days prior to terminate and was told that it will be terminated as per the contract and if i want to keep the number I should call a couple of days after the contract ends.<br> <br> I did call but for days I would be kept waiting to speak to someone and the call eventually cuts so I js gave up and forgot all about that and by the time I remembered MTN was on strike 2 weeks after .Now i find myself owing money for data i never used and whatever lil data i used I thought was due to me since i did have a contract and had not been using my modem that often anyway and had paid for it.The next thing I knew I was being billed R99 but I wasn't aware what it was for and tried to call but because of the strike I couldn't so I reversed it thinking it nust've been an error.I feel ****** and just angry because I thought this contract was cancelled.Please help.<br>