Financial Obligations After Firing Contractor

[Tim G.]

I am in the middle of flipping my 2nd property. I hired a contractor to perform all the work and it's just not working out with them.   Slow work, not on time, excuse after excuse, etc. 

they provided a written 6 week timeline to do the work.  Yesterday started week 3 and I would say they are maybe 1-1.5 weeks into it based on their timeline.  

The total labor cost is $9650.  $750 to be paid at the end of each week and $5150 to be paid when the house is completed.  I have paid them $1500 total for weeks 1 and 2.  If I fire them today, what financial obligations do I owe them?