document, document, document.
Sounds like you have bully tenant which I would not renew the lease. But you can look at this as opportunity as well. Did the problem get fixed correctly by the contractor your tenant hired? If so, I'd consider paying just to make the headache go away assuming that is a fair price for the fix. Again, you have to remember your most valuable asset is your time, do you really won't to spend your time and energy over $360? I understand your trying to make a point and when you mix pride in it's hard but refer back to your most valuable asset, time. One hour with an attorney can chew most of that up. If your documentation is not 100%, I'd check the contractor and repair and if ok I'd pay but would document the situation and have the tenant sign saying ANY repairs moving forward must get WRITTEN approval from the PM or they will NOT be paid. Be firm and professional. This is your property, not there's and it has to be demonstrated. Moving forward, this is something to learn from on future tenants and how important relationships are with them. There are some that just want to be a pain, but for the most part, if your a solid landlord, tenants will follow the rules but they have to know if they don't, there is consequences. I purchase Boston butts every xmas and give to all my tenants just to wish them Merry Christmas and let me know I'm thinking of them. That $50 goes a long way, especially when a problem arises! Good luck.