[tpscruiser]

I believe the A/C system needs to be evacuated and disconnected to change out the power steering pump and then recharged. The power steering pump along with a lot more must be removed to do the timing belt.I think it's safe to assume the system may not have been recharged after assembly or a seal wasn't seated properly and leaked.
I would take it back to who did the job, they should stand behind their work.