1. Check to make sure your SIM card is properly installed and your phone is Unlocked and that 360travelsim SIM has coverage in the country you are visiting.
2. Check you have credit in your account. Credit is required in your account to receive inbound calls. You can check your balance by dialing 187.
3. Try manually changing networks to another provider. It might also help to take out the SIM, re- insert and restart the phone.
4. If you are using a 3G handset check your handset settings to ensure “dual” GSM/3G mode is selected.