A pre-auth is a temporary hold on your account's funds; the duration of the hold can vary by issuer.
An authorization hold (also called a card authorization, pre-authorization, or pre-auth) is the practice within the banking industry of authorizing electronic transactions done with a debit card or credit card and holding this balance as unavailable either until the merchant clears the transaction (also called settlement), or the hold "falls off."
Debit card authorization holds can fall off the account (thus rendering the balance available again) anywhere from 1–8 days after the transaction date depending on the bank's policy. Credit card holds may last as long as 30 days, depending on the issuing bank.
Ultimately, the dollar amount your bank or credit card company is unfortunately out of WRS' control. If a hold lasts longer than a few days, it is recommended to contact your card's issuer to resolve the problem.