Mtn Billing after cancellation of contract

I cancelled my Mtn contract on 24/05/15 as it had experired and I wanted to migrate to an other service provider. I was taken off the air the same day I cancelled my subscription, but still they deducted money from my bank acc. I went to a Mtn shop, but they said they cannot assist me and I must call customer service. Customer service is not available as they are STILL on strike. I am so glad that I decided to cancell my subscription, because this I find unacceptable