it depends on whether they can substantiate the fee as damages or not.


If the payment represents payment of actual damages, then it is different than it being simply a penalty for breaching the contract.

the fact it is a fixed payment with no reference to the basis of the amount tends to suggest it is intended as a penalty but without all of the facts involved, it is impossible to determine with any certainty. You should take your contract to a lawyer who can read it and discover the facts of the situation and give you an opinion.