This is typically due to there being multiple MTurk accounts or TurkPrime users in play (such as, if it is a shared lab account, shared by multiple researchers, a shared computer with multiple users who may log into different MTurk accounts, etc). At times, a user may have funded a different MTurk account than the one which is currently linked to their TurkPrime account. To ensure that the account you funded is in fact the account that is linked, you can click under your account name in the menu bar and select "Setup Mechanical Turk"-->"Edit your credentials". Please re-follow the instructions on screen and ensure that the access keys you enter into TurkPrime are ones that match the funded MTurk account. Alternatively, feel free to request a refund from the recently funded account (Amazon customer support will be happy to help you with that) and add the funds into the currently linked MTurk account.