Product Warranty Dispute — vendor missed delivery deadline

I'm in a difficult situation and trying to figure out my next steps.

vendor missed delivery deadline. I've been dealing with this for about 15 weeks now and the situation isn't improving.

The contract was signed 13 months ago. I am not sure I have the original signed copy. The total amount in dispute is approximately $129,000.

Has anyone been through something similar? What worked for you?

Not a lawyer, but I have direct experience with this.

I ended up having everything documented, which cost about $3-6 but saved me a lot more in the long run.