Tennant found mice dropping in garage.

[Carmel Duffy]

When my tenant moved in 2 weeks ago we mutually agreed that I would be leaving some tools in the workshop until the summer . At that time we would both have a garage sail together. 

She called to say I need to get over and clean up the garage which had spiderwebs and Mice droppings.

She said she needed to store some Antiques and the garage was too dirty.

She then complained that she can barely afford to live in the house and needs to sell out of the garage. I told her I would gladly give her back her money, since she was only there for two weeks and she could find a more affordable place. She is now threatening me with legal action and taking videos of the mice droppings. 

Any advice would be greatly appreciated since I am new at this.

Thanks