Card woes

This week I received my credit card statement.I was surprised when i discovered i had to pay an extra rm150.On checking the details it dawned they had made a mistake!Whether the mistake was a genuine one or an attempt to cheat me of that sum of money..,I don't know.only God and the person doing it knows!!As everything is computerized,my suspicion is that it was an intended mistake with the hope that I would not check.I called and they admitted to their mistake.Now how can or could such a thing happen??Well,it has taught me a lesson.Examine the details of my credit card statements before paying.And I did'nt know that gold card members could have their yearly renewal fees waivered.It should be done early in the year.I'll be requesting for that waiver and i want to know if the waiver should be done in black and white as proof!If its going to be just a phone call,that rm 195 get be easily pocketed by someone!!What people do for some extra money.Don't they know they've got to answer for it when their time comes?