Default [Q] 'Permanently lock' stock rom (Need Help Please!)

I brought the phone via a retailer in Hong Kong and came unlocked, I had tested the phone with a UK sim card and it worked nicely (able to pick up HK networks), brought it back to the UK and was able to make calls and use mobile data.

I recently tried reflashing my phone back to stock rom, it worked however I lost my phone function, I thought the sim was locked however I had tested the sim and it work with other phones. I also typed in the code 2945#*802#, which gave me the menu with all the unlock functions, however after pressing the 'Network Unlock' I received a message saying 'This phone is permanently locked and can not be unlocked.'

Any suggestions to bypassing this or fixing this problem?

Many Thanks! ^_^
Current device: Oppo Find 7 (x9076)
'Diverse Ex-devices': iPhone (Original), (iPhone 3G, 3GS, 4, 4s) Black, iPhone 5 (White), LG G2 (Intl. White), One Plus One (Black Sandstone)
Tablets: Not mainstreaming atm. (Until I find the 'prefect' one)