Have them come back out to check their work. THey should have done it BEFORE they left (and you paid them). It's possible that something is mis-wired or disconnected. Perhaps a valve was left closed.
Call them first. And tell them they should have checked their work before they left! Make sure you don't pay for the $40 or $60 minimum charge and only pay for time and materials on site. (That's what you would have paid them if they were STILL there if they had to fix something before they left. My best to ya and hope this helps.