Lowst my 60,000 Deposit

I decided to purchase a house 2 years ago from a private seller went through the usual formalities, got a Bank in for a valuation who then informed me that the proerty did not have its first Licence of Occupation. However my Estate agent convinced me to go through with handing over the deposit and Rent the property on a 6 month Rental Contract until the licence was Granted we could then complete. After the 6 months the Licence was not granted, so reluctantly agreed to a 6 month extension again. Towards the end of the second 6 month contract there was still no sign of the Licence and at that point I asked my Lawyer to get my deposit refunded as it was taking to long. He advised that I could ask for my deposit back but it would cost a fortune and by the time it went to court the licence could well have been granted and I would have no hope of getting my deposit back. I had no choice but to take his advice, it took a further year for the licence to be granted. By this time the market had collapsed, the property was valued at 350k not the 750k I was paying. I tried to negotiate the price taking into account the market and currency issues and was told to get lost and move out. I had no choice to move out and forfeit the deposit. My question is was my Lawyer correct in saying I had no chance of getting my deposit back even though we had agreed a 6 month rental in order for them to gain the licence, or should he have advised me to take legal action for recovery. Also as the sellers had not not fulfilled there end of the bargain by not gaing the licence after the first 6 months was I not entitled to recieve my depoist back. If I have a chance legally I am happy to offer a 50=50 fee, or am i completely done for.