What would you do in this situation after months of tolerating it.?

I would go speak to my neighbor. Then, if they kept doing it, I would follow up with a phone call or letter to the management company or owner. In fact, I'd send the letter "As per our conversation...." just to have a paper trail. Good luck

I know how you feel, I used to have kids living upstairs throwing crayons and toys to our patio, coupled with trash and cigarette ashes. The only way is to politely show them how much of their stuff has ended up in your place and request constraint.

Call the apartment management about it, every time they do it.

You're christian, you deserve it.