Consumer Law, Warranties Fence Contractor caused damages - withhold $?

[fubar24x7]

I had a fence contractor replace an existing fence. One of the workers damaged a drain pipe. Contract says we are responsible for this as it was not within the OUPS markings but this worker pounded on the 6" storm drain pipe repeatedly. My husband had to tell him to stop. We ended up having to repair a 2 foot section and it cost us around $100 for materials. We completed the repairs ourselves because they were just going to "cap" it - it would not have been to code. Can I withhold the $100 for the material from the final check? I want to charge them for our labor too but wasn't sure I was allowed. I do not want them to have any way of putting a mechanical lien on my property. I have all receipts and pictures to back up my case.
Any assistance would be appreciated.

 

[Michael Wechsler]

Why not discuss this with the company first and make an agreement. Send them a copy of the bill and mention that this is the amount of actual damages caused by their worker and that you will send them a check for the remaining balance, less your out of pocket costs, and the job shall be deemed paid in full. Right now it doesn't appear there is any dispute yet.