need help with a disput issue.

my dispute issue is this. i did a job for a person back in august that involved having to use my pickup truck to haul equipment. on the way to get the equipment one of my tires blew out which was not expected. the person i was doing the job for was the passenger i was able to get the truck to the side of the roadwithout incident. we ended up getting a tire from a tireplace that did roadside assistance. this person paid the bill with thier mother's credit card. the person also said that the money from the job will pay for the tire and i had nothing to worry about and the tire was mine. i never once asked for money from the job. the tire has been on my truck for over 2 months and now they want this tire back.. what should i do? keep the tire?