It's just a matter of time...
Your poor Meezer darling must be quite frightened, probably been through an awful ordeal. Kitty just needs some time to adjust, this varies from cat to cat as the others have been saying. My housemate adopted a cat which hid for days, but now is so affectionate that he sleeps on his human's face.
Pixel, on the other hand, needed about 5 second's adjustment time before she was rolling over for scritchies, helping herself to some food, and scampering about.
Good luck, and welcome to PT. We want to see some PICS!!!!