transaction issues

I'm having issues making transactions in the marketplace for the items i want, after implementing the stuff i want and my card info after clicking the place order a error popes up that say

there was a error completing transaction this has been happening for three days and there no sign of me making my transaction

You want to go here:

https://support.dndbeyond.com/hc/en-us

You're posting in the community forums where you're most likely to find assistance from other community members, and mods and the like.  The link takes you to D&D Beyond's actual customer service system with I'm told a whole ticketing system available to support you on transactions and the like.

oh oops thx

No worries, it's pretty common.