Thank you very much for your comprehensive answer.
I now see why the lawyer did not trouble himself to persue the developer for my Bank Guarantee.
He arrogantly regarded providing it as the developer's duty and knew that if anything went wrong with the transaction the blame could be pointed solely at the developer.
He was doing the minimum work for his fee, and he was protecting his own interests first...not mine.
So why did I pay him for PoA? He was paid to act on my behalf and protect my interests.
How does a lawyer aquire the swankiest suite of offices in Marbella when he is so negligent with his clients affairs??

All I wanted was a holiday home in the sun to spend our winters in a warmer climate.
Now, like thousands more,we have lost our money with no chance of being able to afford another property. All our hard work and dreams have come to nothing.
Just one more question. Do you know how many Spanish citizens been caught up in the problems caused with the lack of or failing to produce bank guarantees or is it predominantly affecting foreigners?

Yes, you're right about 'Patience'. But I think that even a saint's patience would be tested when trying to purchase property in Spain.