Agreement related to ownership

[Brian Whetstone]

Hello!

I have a question/advice from this trusted community.
Went into partnership with a person last year on a triplex. He qualified and holds the loan. Mid last year He wanted out of the deal completely for personal reason. We drafted, signed and notarized an "agreement related to ownership of real property" Stating ownership shares, and income splits. 

Fast forward to today, the loan holder is wanting back 100% of the deal and disregarding this agreement. 

What level of security or actions can be taken on my end?

Replies are highly thanked.