I would assume your reference to "full roaming package" means a billing add-on which doesn't enable the roaming facility. Did you confirm that the roaming facility was enabled on your phone before leaving the UK?
You will need to contact EE C/S from another working phone (+44 7953 966250) or a web-calling app (+44 800 0798586) if roaming isn't enabled. If it is, then rebooting your phone or manually selecting an alternative local network - may resolve this.
