I was awarded a judgement in small claims court. I filed a writ of execution but when I called the debtor's bank they told me they had to notify him. This will only allow him time to close that account. What else can I do to get a levy on his account?

Welcome to AMHD. I don't see where you are from; law varies somewhat from state to state. In my state, a writ of execution is different from a garnishment.
"A writ of execution is a common court order granted by a court in an attempt to satisfy a judgment obtained by a plaintiff. When issuing a writ of execution, a court typically will order a sheriff or other similar official to levy property owned by a judgment debtor. Such property will often then be sold in a sheriff's sale, and the proceeds remunerated to the plaintiff in partial or full satisfaction of the judgment. It is generally considered preferable for the sheriff simply to confiscate money from the defendant's bank account. If the judgment debtor owns real property, the judgment creditor can record the execution to "freeze" the title until the execution is satisfied." Writ of execution - Wikipedia, the free encyclopedia
"A garnishment is a means of collecting a monetary judgment against a defendant by ordering a third party (the garnishee) to pay money, otherwise owed to the defendant, directly to the plaintiff." Garnishment - Wikipedia, the free encyclopedia

In my area, a garnishment is used to authorize an involuntary withholding from the defendant's pay, or to seize a bank account.