Trouble unlocking Sony Xperia XZ2

[Lyns1]

Hi, O2 say that the XZ2 I bought from them isn't locked, the Virgin sim says it is. The Virgin sim works in another phone.  I've requested 3 times 'unlatched' through O2 (once myself using the app +

 twice by calling O2 helpline).   After it didn't work for the 3rd time I called again.  Advised to turn it off and on again and also try a network reset but didn't work.   Said nothing else they can do as they think phone is unlocked even though it's definitely locked.  Have gone through the details with them.  IMEI etc definitely correct.  Can anyone please advise? Thanks

[MI5]

@O2Emma 

Can you help please?

[O2Emma]

Yeah no problem @MI5 

[O2Emma]

Hi @Lyns1 have you received any unlocking instructions with a code on via email at all.

[Lyns1]

Hi @O2Emma , no I just got messages saying that the phone was unlocked and this was confirmed by customer service when I called even though phone still says sim locked by operator

[Lyns1]

@O2Emma , message copied below 

Thank you for your email.

The IMEI you have provided has been returned from the manufacturer as
not being locked.
Check another networks SIM in the device to ensure it's actually latched
to which network.

[O2Emma]

Ok @Lyns1 what message on screen do you get when putting virgin sim in please.

[Lyns1]

@O2Emma It asks for an unlock code. I put in 7890 which came with the sim, it says it's unsuccessful. Sim also has a 'personal unlocking key' so tried that.  Every time it says it's unsuccessful.  Called virgin, they say issue is with O2 handset but gave another set of unlock codes to try just in case but didn't work.  Also when putting virgin sim into another phone it just works without asking for unlock code.

[O2Emma]

@Lyns1 If you can check via this link https://www.sony.co.uk/electronics/support/articles/00235502

This will tell you if locked how many attempts left.

Also it sounds like the code you are entering would not be a unlocking code they are more to do with sim lock which would of been set up on device itself .

[Lyns1]

Hi @O2Emma , unfortunately this link doesn't help.  I haven't been given a NUC code by O2 as they keep telling me the handset is unlocked