LG G4 unblacklist

Hi Guys I bought a LG G4 from ebay and it worked fine for around 2 months and then all of a sudden it started displaying no network. I have contacted vodaphone as it is on the vodafone network and they informed me that the phone has been blacklisted. I was wondering is there a way to unblacklist this phone.
There was a guy on ebay who does the unblacklisting process remotely at a cost of $ 45 sop i went ahead as it stated the process will be done remotely. The guy i paid does not respond now at all he has taken the money and does not reply.

I wanted to know is there a way this phone can be fixed??? Can it be done remotely?

Thanks for your help.