If your 360 gets a red ring of death, which is the most common failure, Microsoft sends you a fed-ex box. You pack it up, put it in the mail (free of charge) and they send you a refurbished one in a couple weeks. It's pretty painless, unless you are a crazy person who can't handle being without a console for a few weeks (which seem to be all over the MS forums.)
Surprise surprise, Xbox (not only xbox but all electronics) customer support in whole ex-eastern europe (he is from serbia i am from slovakia we know what are we talking about) sucks walrus balls... Solving most of the RMAs is as painful as hitting your balls with hammer... Because afaik xbox is not handled by MS directly here, but by some 3rd party business...
EDIT: You are realy lucky that you have that kind of support, but in here, it would be miracle if i got the unit sooner than in 30 days... and 30 days without thingie which i paid 300+ EUR for, is not very good deal imo...