lol, if they were real life friends, that left you over than, then f*ck them, they're not worth your time.
if they were online friends, tell them to nut up or shut up, and stop being so butthurt about hacking a game that gives you no real advantage anyway.
either way, its not worth going back just because they got pissed, consider it a blessing that their true colours were shown over something soooo petty.