Bad Service and payment gateway issues

I signed up for web Africa for the capped ADSL, I tried paying with my Capitec Master card, which works everywhere else online when I pay for things with a master card, but not on Web Africa's site. The site gave an error:\Invalid transaction""; I then received a call and they told me that it was to late in the month to pay via debit order and that I need to pay via bank deposit. Thanks for all the inconvenience and making me feel like its my fault that my master card did not work on your site. You have lost a customer. There is no option on your system do delete my master card details from your system;this is a serious concern to me. Please delete my card details when I leave."""