If the money was charged but your wallet still shows nothing, it’s probably stuck in processing. Restart Steam, check your purchase history, and if it’s still missing contact support.

You probably just need to wait. If the transaction succeeds you'll get the money then. If it fails you won't. If it's pending you need to wait for a resolution. You have no control or influence over the systems involved. There is nothing for you to fix... unless you put in bad data in for payment that wasn't caught in initial validation. When the transaction fails, put in the right data. But that's IF, any other normal scenario means there's nothing for you to do.