@qwertypoiu why are they charing for a new hub thats 14k if i remember correctly on its own, bearings should be available seperately and for me they only changed front bearings which ousted around 4k not the whole hub. and are you sure its rear bearings? put the car on the lift and put in drive and get it 80-100km/h with wheels off the ground if you dont hear a noise that means your rear bearings are bad, its rear for rear bearings to go bad this soon mostly its the fronts.
if the rear bearings have infact gone bad and they are only available as part of a new hub and not separately then you have no other choice. plus driving with bad bearings is dangerous and you should get this fixed soon.
if it makes you feel any better one hub with bearings for my w203 is 27k.