Top-ups now charged, without notification

I was so surprised when I checked my bank statement, I had been charged three times this month for airtime top ups. How this happened, I don't know, because I looked at the 2015 pricing guide, and it says all top ups via cellphone banking are free.<br> What irritates me the most if the fact that I sent them an email last week to query this, and up to this day, I'm still waiting for an answer.