When is property left after closing considered abandoned?

Prior to closing we let the seller know we were not interested in the kitchen table in the house, so we were told it would be removed. On the day of closing we let them know the table was still there. They agreed to come pick up the property that night, or that weekend. Two weeks later I emailed the realtor to remind the seller we still had their table. They said they would pick it up that night and we could leave it on the front porch. It has now been 3 weeks since closing and they still have not come to get the table. We have witnesses for all agreements; both verbal and written. How long do we have to wait before we can consider the table abandoned and part of our personal property? (This is in the state of Michigan.)