I'm glad Andrew posted a welcome, because I missed that you were new. As a result, I'll add a friendly "hello!" and a disclaimer that the following post should be seen as more inquisitive than accusative. I'm not trying to scare off the new guy!
In less legal wording , if someone tricks you into making a vow based on a false premise I do not believe you are bound by it.
I'm going to have to question this based on the experience of the Israelites being tricked by the Gibeonites in Joshua 9. God seems to hold them to this covenant later (e.g. 2 Samuel 21) when he sends a famine for Saul's breaking it, and David has to make attonement. Another example would be Isaac being tricked into giving the blessing to Jacob rather than Esau -- no take-backs!
This is confirmed in the following law:
Leviticus 5:4-6. "'Or if anyone swears rashly with his lips to do evil, or to do good, whatever it is that a man might utter rashly with an oath,
and it is hidden from him; when he knows of it, then he shall be guilty of one of these. It shall be, when he is guilty of one of these, he shall confess that in which he has sinned: and he shall bring his trespass offering to Yahweh for his sin which he has sinned, a female from the flock, a lamb or a goat, for a sin offering; and the priest shall make atonement for him concerning his sin."
Of course we have forgiveness through the sin offering* of our Great High Priest, Jesus Christ, but I don't see Biblical precedent for rash vows to automatically be declared null and void.
(By the way, for this same reason, I have decided to stop saying the pledge of allegiance. I am thankful to God for my country, and obey its laws insofar as they do not contradict God, but I will no longer vow my unconditional future loyalty to a system that does not honor God.)
*Autocorrect tried to change this to "son offering" which would, technically, also be correct.