Multiple charges on credit card?

So I was trying to upgrade my trial account to vanilla WoW, but I got the Error #202 message when I tried to purchase a digital download upgrade. I tried a few times, triple checked the info, but still I was not able to purchase the upgrade. I was looking into a fix for this (I've still found nothing, but I'm probably going to have to call customer support). Anyways, while I was looking into if other people had experienced this problem, and while I was, I noticed that some people had received multiple charges for "holding funds" on their bank account.... I was using my mom's credit card and if this happens it's gonna be pretty bad. :/ So I'm just wondering if this happens with specific companies/card types/if it ALWAYS happens or not... if it does this would be really ridiculous especially since I couldn't even purchase the upgrade. If somebody could respond quickly it would be really appreciated I'm sort of worried because I tried at least over 10 times so if a charge for each try happened it would be... well, very bad. :( Of course, since I'm using my mom's card I can't check her balance to see if she was charged multiple times which is why I'm asking you guys for help.

(Also, off topic, if anyone does happen to know a fix to error #202 WITHOUT calling customer support it would be great, but don't bother yourself over it)