Can't unlock my old phone. Double blocked?

[Lidija]

Hi. I didn't know, that to unlock my old phone with finished contract, I had to put a request. So instead of o2 network PUK I entered my new sim PUK code few times. After I had chat with o2 community and received code for unlock, but still nothing happend! How I know, if made 3 mistakes, phone will be blocked, and how I understand, its happened with my phone! What to do next? How to unlock my phone? Why it is so difficult? 

[MI5]

No disrespect to anyone but this thread should not be marked as solved.
It is not the answer to the question but O2 will never be able to provide the answer either.