My cell phone case wont come off my phone?

I bought a case for my blackberry, snapped it on and now I can't pop it off. Any help?My cell phone case wont come off my phone?
If its a plastic (Jewel) case then it may well be a bit difficult to get off cos its new. Try perservereing with a blunt knife to get into the join but be carefull u dont wanna cut urself. If its a fabric case then the secret is to push it up out of the case from the outide. If u find its a bit difficult then ease it open at the top of the case with ur other hand :) Hope this helps