Well, the first thing you should have done is step back, assess the situation and any evidence you have for your position, before denying the Resolution Center claim.
At this point, if the host escalates, they get to present their side of the story first and you look like you brushed off the claim.
You then get to present your side of the story.
I would stick to being factual, proofread and review carefully before submitting, and avoid making wild, incendiary claims such as "I suspect he is in debt and wants to shake me down for money," which may reflect negatively on you.
This is a factual dispute. Present the facts calmly and without embellishment, and the facts should prevail. Stray into personal accusations and needless hyperbole while the other party is calm and factual, and you may lose.