MTN sucks

Made the worst mistake of my life and migrated to MTN signed up a contract that I was not aware it was binding me. Now I want to cancel it and remain on prepaid the worst network is telling me about paying the early cancellation fee that I told them that I won't even be able to afford because my reason for canceling is that I'm now unemployed. When I don't pay the mere R99 I must pay monthly they deactivate my line. I made a stupid mistake for migrating to MTN I going back to Vodacom and will stay there forever. Please guys don't do the mistake I did