Question

I am a sub-contractor with a signed contract to preform 40 qualified demonstrations in one month. My month is up this Friday, April 17th. I have set all the appointments for the remainder of my qualified demonstrations to meet the contract. My employer told me today that because a trainer was not present during 3 of my demonstrations, I will not be paid. My contract stated that I am required to attend training for 3 days which I completed and no where on the contract does it state that I have to have a trainer with me to do a demostration. I had a trainer with me during my first few demostrations. My employer stated today that do to certian circumstances, I needed a trainier with me during this weeks demostrations. They have requested that I cancel my remaining demostrations and turn in the machine today. If I cancel and turn in the machine, will the contract still be upheld in a court if I have't completed these demonstrations?