HELP: My data connection just isnt registering on my new LG G3

A

AC Question

I just bought this new Lg G3 UNLOCKED on eBay from a Melbourne store (i am from Melbourne) and from the moment I've put the sim card in I've had problems with data connectivity and reception in general.

My sim works just fine in my old phone and so does my reception. I even tried putting my friends SIM into my phone and it still didn't work.

I've been on the phone with my service provider for hours trying to resolve the problem (checking apn settings, resetting apn, restarting and trying again) and still nothing has worked. My 4G data is still not showing up.

Also I am having problems with the phone just randomly cutting out when I'm on the phone with someone, and it's happened to a number of people I've been on the phone with.

When I restart the phone a warning sign comes up specifically saying "WARNING: Current version is not available for user. Can't find matched cust for NT-code mcc/mnc[310260], subset[FF]"

I really like this phone and don't want to have to return it, just want my data to work!

PLEASE HELP ME