What can I do about an upstairs neighbor who won't fix his leaky tub - which is damaging my bathroom's ceiling?

Anything will be complicated. The first thing is to go over your condo agreement, and see what the association is responsible for, or how they are supposed to mediate this. The second option is to do repairs, and go after the neighbor for damages.

do not pay for the repairs to his tub!! Call a lawyer and have him send a letter to your upstairs nood-nink demanding repair of your damages. This should be a no-brainer for a good attorney.

You’re obviously not going to win this with words.

Bring in the law. He who wields the strongest lawyer, wins.

call the landlord. i had a similar problem back in the 1980s in my studio apartment.

@charliecompany34 There are generally no landlords in condos (landlords exist where rentals do, and a condominium is ownership), and the poster already mentioned that they had contacted whatever company is in charge (the one who takes their condo fees) and was met with a “go away” answer.