Contact cancellation

<p>Extremely unhappy with the fact that I have cancelled my contract in April already. Been to that shop 3 times to cancel before. I want the money credited. Now they tell me that because the airtime was used they will not credit it. I just want to know how is it my problem if they kept the contract going after I cancelled. </p> <p>********* to say the least. It's a f.up from their side not mine. I have proof of contact cancellation for April. </p> <p> </p>