Taming savannah monitor?

Hello, I bought 8-10'' size sav. monitor two weeks ago, hi is not aggresive, doesnt bite but is really scared, it won't come out from his hide, and whenever I handle him hi gets stressed out and tries to get away from me. Im not a beginner, I had savs before and the enclosure is right for him. the pet shop told me its not wild caught. So any suggestions would be apprrciated. thanks.