Do I owe return of pet deposit?

[Vickie Bruce]

Back in December of 2016 I made a huge mistake and rented to 2 young men who worked in the oil field.  I thought it would be great because they would be gone 1/2 the time.  Soon after they moved in they backed over a gas line and left the property without telling anyone what they did.  We had to call gas company to shut down gas and repair.  Next they tampered with the hot water heater and burned it up.  Next they brought in a dog without asking.  These renters were hell.  One night they were doing donuts in our hay field.  I approached them about the dog and said they would have to have a seperate pet addendum to have the dog and pay a pet deposit.  In their lease it stated that but they never paid any attention to the lease.  After nearly being evicted because they would not pay, one of the tenants brought over 300.00 for the deposit but never even asked about the addendum to sign.  I didnt think it was important since they did pay.  Next they brought in horses and made use of our barn which we told them no to.  Finally I had enough and told them we were renovating and they had to move.  They left a mess. Half painted cabinets and wall and doors.  Never had trash pick up and was all left in garage from 1 year.  They left and never returned keys.  It was a nightmare but I was happy for them to be gone.  3 months later they are asking for the first time their 300.00 pet deposit back.  Do I owe it to them?