IMO, not a lawyer btw, it is unreasonable to hold on to the full deposit no matter how the contract is agreed, especially in your case.
There might be “administrative” charges but certainly not forfeiting the full deposit and the “administrative” charges must be reasonable within the industry.
The opportunity cost of turning others away is simply just an opportunity cost. i.e. a prediction or projection or forecast. They need to proof that they actually turn others away.
Even if they do then perhaps you should ask why others were turn away? Because it does not make sense to favour you and not others. i.e. are other people being turn away because they are going to pay in Peso or some weird currencies? If that is the case then there is no opportunity cost. The question then should be why the others were turn away in favour of you? Are you more gullible? Have you been coerced in agreeing? Even if you got cold feet now it only proof that you were not certain from the start go.
Yes, you should be able to get back your deposit minus “admin” charges.
In your situation the forfeiting of the full deposit is simply due to greed. There is no justification at all.
The law should be fair and not one sided. Paying “admin” charges is fair but forfeiting all deposit the law of the land is kucfed.
Don’t stand for it. The law should be fair and should not to be the instrument of bullies.
🙄