Refund

I had a home internet contract with mtn it ended and they told me i must still pay a month to cancel it bt i dont need to worry my last month will be refunded because i didnt use it handed my router in October last year already here we almost in October again yet no refund it shows on the system my refund is there i went to so much mtn stores nobody can tell me why its not being processed into my account was told i had to call online called them bt still nothing