no one seems to be bothered

My contract has expiredbeginning of April and i contacted the call centre and was told to phone after the call9th of April. On the Ford20th of April i phoned again the call centre and advised that my number will be migrated to prepaid after the cancellation. Ever since nothing has been done and i had to call again on the 30th only to be told that my contract is still not cancelled . I am very disappointed with mtn and would like my query to be resolved as soon as possible. I don't want to be billed for something that I'm no longer benefiting from.