pulling out of a property deal any ideas

hi all iam in the middle of what seems to be a on going drag i have bought a house and land deal in qld through a buyers agent company in melb and with the val coming up short a few months ago and the dates keep geting pushed back and back and not a good response from other agents in the town it self i have come to decide to get my self out!!!!!    now my problem is the company and the lawer said the contract has a 18 month sunset claws in there its been 12 months so 6 to go till i could walf free !!!! so theve stated i would loose my 5% deposit of land cost now the company has said they cant do no better for geting me out the have advised i get the lawer to do his best his suggested i get them to do their best!!!!      the lawer was referd by them from the start iam wondering if any one has a opinion should i get idendent advise on the legal side???? and just today the company noted there was no relase date so that makes me not suprised but unsure where that can lead me in to exit stragery      regards dan