Mtn Contract is a ****

Canceling a contract with Mtn is such a drag... they are a ****. I contacted them via email wanting to cancel they told me to pay an amount for the cancelation. I went to their shops in Kimberley and the assistant told me i need to pay an amount of R740 which is outstanding before i could cancel. Now they blocked my sim card telling me i need to pay another R710 which is outstanding in order for me to cancel my contract😡. That time iv been sitting with a blocked simcard for weeks.