By the sounds of it, you are entitled to a refund but the manager is just being difficult to avoid having to pay you.
There are two possible courses of action you may take.
First, it may be wise to send the manager a 'Demand Letter'. A Demand Letter is a letter that demands a person take a certain action otherwise you will pursue legal action. In this case, you would demand that he refund you the $40,000 he owes you, lest you commence legal action against him. The goal of this is to nip the issue in the bud by resolving the matter before it has to go to court. However, if he doesn't comply with the Demand Letter then you are left with little recourse other than commencing legal action. I understand that you have contacted him and perpetually demanded payment for several months, but a Demand Letter is generally sent on your behalf by a lawyer (and on the lawyer's / firm's letterhead) and signed by the lawyer- this makes the letter more intimidating than just you contacting him and demanding it without the imminent threat of legal action by a lawyer.
The main benefit of the Demand Letter is that it is relatively cost effective and will lead to a prompt resolution if he is agreeable to comply with the demand.
If that course of action fails, or if you don't think it will work and you just wish to skip it, then you can commence legal action against him. If you wish to do so, the first step would be to issue a Statement of Claim (document that sets out your legal claim against the party, and is the first document used to commence a lawsuit) against the person.
In conclusion, the best course of action would likely be as follows: Send a Demand Letter- if that is unsuccessful, commence a legal claim (lawsuit) against him. In this Claim, you would claim the $40,000 back as he breached the refund policy. You may also claim interests as well as the costs you incurred to file the Claim.
Hopefully that is of assistance.
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