said by mattmag:The only mistake they made was not putting a 240V dual pole breaker in the main house panel which is all they touched. The existing poor garage wiring existed before and they weren't touching that. Sorry if that wan't clear. I can handle purchasing a 15 dollar breaker.
I'd call your electrician back and have him fix his screw-up. If you knew it wasn't right, he sure as hell should have known too. Direct-buried only a few inches? Too short to reach the panel? Was he a real electrician?