No expert but yes, find the setting to turn off WAP communications as that is over the service providers mobile network and costs. (Mine is permanently off.) If you want Net access try to find a free WiFi hotspot.
Probably best to turn off voice mail too to stop you being tempted to call in and listen at international rates. (Mine is permanently off.)
Remember if you asnwer a call the caller pays for the UK part, you pick up the bill for the more expensive international/local leg. You may wish to reject calls and initiate any calls you think important, yourself. If the incoming call is important they could always text first.