does Spanish Law override terms of a spanish contract?

we are in the process of selling our spanish apartment but the apartment was bought by another agent who believed he could sell it on (for a killing we imagine) however the vendor he thought he had has disappeared and to date he has not managed to secure another buyer. We are committed to the contract until 24 August whereupon we have been told that if there is no other buyer the agent will forfeit his 3k euro deposit. The terms of the CONTRACT say that if cannot continue with the contract he will lose his 3k but is WE withdraw we have to pay HIM double the amount of the deposit ie 6k. Understandably we have no desire to do that! We didn't question the terms of the contract until, independently, it was pointed out to us that SPANISH Law says that we too are entitled to 2 x the deposit paid in the event the sale does not complete so we should also be entitled to 6k euros. Therefore does Spanish law actually override the terms of a Spanish contract and should we contest our entitlement?

Dear Sir

You have been misinformed.

To apply what you write it has to be expressly worded into the contract as "arras penitenciales" following Jurisprudence of Spain's Supreme Court.

So in your case you, or the agent alternatively, will have to pay what has been agreed if either of you should withdraw from it and not honour it.

The agent will refund you with €3,000 or else you will refund him double said amount if you withdraw.

Yours sincerely
Raymundo LarraÃ*n Nesbitt