MTN service

Hi , pls help me ,tuk a contract with mtn to pay R159 opted for te prepaid option ,after 3 weeks of strugle my sim card was activated ,then i bought airtime bt i was suprised dat it was not finishing ,i called mtn cc to find out what was going on ,but the phone was just ringing with the voice recorded lady talking ,den i went to mtn to ask about it ,i ws promised dat al will be well & i mst not use the tablt for calling as it will charge me , which was nt advised to me , after that i got a masage that my sim card is stopped and since den i cant use it as it is not active , its been 3 weeks with me not hving that card as it is discornected , i asked for assitence via email and i was advised that i must pay before they can activate which i think its not fair as i did nt ask for open line my debit date is on the 30th and there is no day that mtn never got their money from my account, i was advised that i must pay cancellation fees for migrating to prepaid Y should i pay for it if i didnt ask for it? i requested for prepaid at the shop & it was not done , nw as a customer i must suffer for the mistake done at the MTN shop? my emails have been escalated to each agent and noone is anwes