i need to unlock my carrier network

i been in touch with my last carrier, where the phone had been purchased and seem that from them there is not restriction policy to the carrier network. i replaced my iphone after 5 years in italy (iphone both in london), for a damnage i been in apple store in milan and paying 200 euro i replace it... three uk doesen't have any look to my phone, and 'm unable to use with different carrer!!! this is totally crazy and insane...

thanks for your reply, i been in touch with three uk, witch was the service provider and where i actually got my iphone 7 plus.

from them, after checking my imei code, there is no restriction or looked after checking my imei code. after 5 years, i broke my iphone 7 plus, i was in italy and i replace my iphone in milan at the apple store paying 200 euro. Apple can not do anything to unlock and update my carrer ntework setting, the provider can not do anything to unlock and update my carrer setting, so, can please anybody tell me what can i do to use my phone with a different card???

by three uk website, appear a message saying "if you purchased your device after 1 January 2014, your phone is already unlocked". i had a chat with three customer service, and the operator told me, after checking my imei number, that by three doesn't appear any restriction on my iphone. believe me, i moved to work in caribbean, saint barthelemy, and is about one year and half i'm fighting with this problem. WHAT SHOULD I DO TO UNLOCK MY IPHONE 7 PLUS witch is working perfectly???

i actually payed 220 euro to get a new phone restored, i gave my broken one back to get a new phone iphone 7 plus, this 3 years ago... after taht, i both an italian sim card, still from 3 carrier provider, and it was working perfectly. i contact three ita and three uk, and both of them told me the same thing, by their company there is no restriction by the carrier network provider... i'm getting crazy with this issue, strange thing is that, why a company as apple can not FORCE the network setting if someone having that kind of problem??? as i'm unable to use my phone with a different carrier, shoul i throw it away and get a new iphone? this is insane... i don;t care if i have to pay a fee to unlock my device, i just would like to get my phone able to use....

ok this is good to know... but my question is still the same... i have nothing left to pay as my phone contract is expired, all the check were payed perfectly, three uk saying that if i purchased my iphone after 1 January is already unlocked... i did a restore by itunes, and no network setting update has come up... so, still when i insert my new sim card from orange caribe, appear a messag SIN NOT SUPPORTED FROM THE ACTIVATION POLICY. this issue is driving me totally crazy... and i don't want spend 1300 euro to get a new iphone as mine one is working perfectly!!!

i used just 2 sim card, from three uk, and from three ita.

my iphone has been purchased from three uk, london, oxford circus, if there is any block, must to be just from them... appparently by their data center, my imei should be free... ****!