You can call them up on the telephone?  Email the company at contact@companyname.com or some such address found on their web site?  Or if they do not have a web site, you can next day ship something like a blank memory card for your PLC with requested changed to be loaded onto the memory card and shipped back for you to install.

If they require a password to restart after power on, it is time to find a new supplier, or pay the bill (in case your company still owes that supplier for the equipment). 

Habeib_nader

Thank you very much Hati.

But I don't have any contact with the supplier