DISAPPOINTED IN MTN SERVICE

i called in on the 19 May 2015 to cancel/deactivate MTN contract and put over to Prepaid, didn't want to renew my contract. called in to customer service spoke to Fezi and and he said after 3 days it will be changed over to Prepaid. at the end of the call told him to sms me the REF number.. didn't get any sms thought its a delay on MTN side... forgot about it. 1st of July i still got debited which is wrong because last debit should have been on the 1st of JUNE.. had to go into a MTN store to cancel contract yesterday when i had a chance. which mean im going to be debited again i am very disappointed in the service i got from the customer service... i would like to be refunded for both months... and the only proof i got is the phone call that was recorded on my cell phone for situations like this.....