Firstly game works online no probs. I've been playing online for months.
I recommend having a mobile banking app (i.e revolut, Starling) so that you can just add the currency needed. or you can use paypal.
Download FREE vpn UrbanVpn via urban-vpn.com/
and install it.
Right click the tray icon once installed and select Europe > Ukraine > Connect
Let to connect.(Popup should display to confirm)
Navigate using your internet browser to battle.net
and then click Games > Call of Duty Modern Warfare. You should now see the page below
It will display the prices in RUB which is Russian Ruble. BUY NOW
DO NOT USE YOUR blizzard account (if you have one) Just register a new account and it will assume you are in Ukraine.
Standard Edition is £16. As per currency conversation.
Us in the UK are getting ripped off as the same website wants £37.99
Be prepared to wait an eternity for the download and install.
PS. Dont forget to uninstall UrbanVPN.