How can I fix my w810i sony ericsson? A question about puk being blocked?

I tried to change my pin for a security lock.. every time I changed my pin it would say "wrong pin" and then it asked for a puk number, me being very persistent, kept typing in random code that seemed to work, now my phone says "Puk blocked, contact provider", it only accepts emergency calls, and I really don't know to get out of this mess, can someone please tell me how to fix my w810i? Thank you.