blackberry 9800 4gb faulty no service in uk to use abroad only unlocked *

blackberry 9800 4gb faulty no service to use abroad unlocked.it wont work in uk will show the network but when u make a call it says call failed. it has built in 4gb memory phone is in good condition apart from the front bazel has glue on it.it can be removed if u know how to..contact 07852822877 the phone is in fullly working order apart from it wont make or recieve calls in uk but will fine abroad its unlocked to use abroad.al the other functions works perfectly fine..