The short answer is: IT DEPENDS! And as already pointed out, you have a combination of issues involved here, that involve BOTH verbal and nonverbal contracts. Only an experienced attorney with knowledge of ALL the facts and circumstances can provide you with the best and correct course of action for you to pursue. So, YES, I would retain the services of an experienced attorney ASAP! As an aside; if you found my direction helpful and if you feel appropriate; could you be so kind as to designate my answer as the “best” answer to your question? I truly wish you the best of luck in pursuing this matter!
Many more facts are necessary, but left out. You ask about a verbal contract, but then it appears you signed something. They foreclosed, but you did not say why. Presumably, you owed a debt you did not pay. It seems you should be asking about the foreclosure. No one here has the documents and the rest of the facts. You'll need to see a lawyer - something that should have taken place well before a foreclosure. There is no way to give you an answer here (other than yes, may verbal contracts are binding).
Not all verbal contract are binding, especially ones that relate to the sale or interest in land as those are governed by the Statute of Frauds. However, part performance of the contract can take the contract outside of the Statute of Frauds. You do need to see an attorney as the contract may be voidable.
This is not intended to create an attorney client relationship and none is to be implied either. You must contact an attorney and present all facts before you can and should act on this response