Can your boss stop your direct deposit without permission?

Employers may choose from several options how they will pay your wages. See A.R.S. 23-351(D).   If they choose to pay you by direct deposit, they must have your consent to do so, but they are no obligated to pay by direct deposit if they do not want to. Unless they have otherwise promised to pay you ONLY by direct deposit, then they are likely free to switch to another payment method authorized by statute.  They must, of course, continue to pay you (subject to withholdings, garnishments, and other authorized or mandatory deductions).