Community experience with Anet purchases when money is billed without ur knowledge?

Hi, so today i woke up to find an amount of money charged to me for a transaction that I didnt make. I previously purchased some gems and PoF which came through without any problems, but this newtransaction was not made by me. After checking in game, I realised nothing was purchased on my account, which leads me to believe another player has been making purchases using my bank details or this was just an innocent mistake on Anets part. I have already opened a support ticket, and have not reversed any purchases, as I understand taht arena net insta bans ur accoutn if u do that. I have however contacted my bank to deactivate my card from having anyfurther purchases made until this is cleared up. So my question is, has anyone else experienced this and if so how was it handled by Anet. Im honetly hoping it was just an accident with Anet, and not another account that managed to get my card details.PS. I only have one account on gw2