oooh i too feel your pain!

the thing that REALLY irks me is that they let you MOVE INTO a stinking cess pit of grime and filth, but when it comes time for you to leave, the place needs to be a frikkin' better homes and gardens show home!!!! ARGHH!

we were once bitten by something similar. we fought it all the way and they backed down, but we have learnt our lesson. now with every house we move into we take photographs before the furniture is put in. and i make sure that i take close-up shots of any mould, stains, dirty ovens, marks, cracks etc. it is a real PITA, but since then we have had no issue. we also go over the condition report with a fine tooth comb and add EVERYTHING we see. even if it is a slight shadow of a mark on the walls. sounds crazy, but i feel heaps more comfy for when we move out. no doubt they will kick up a stink though...

i hope that things can be sorted for you guys and it can get resolved with no cost to you.