Mtn
MTN not willing to refund my airtime

I bought the Blackberry Internet Service on my Z10. I realised that despite having been charged the initial R59, my airtime was still being ''utilized'' when browsing the web. So I called the MTN customer care-line. Only to be told that "BIS" doesn't apply to the Q10. To make things worse, they wont refund my R59. Why was the option there?