Is the reason you are posted on a public tree because the tree owner has listed a death date? I realize you are not deceased, obviously.
It sounds to me as though the tree owner has obvious errors on their tree. The tree owner may not even have an active tree. Can you add a comment?
It could be the tree owner has someone in their family with similar information, similar birth year and similar name, maybe even similar parental names.
I'd like to share a story that is somewhat relevant. When my father died in Orlando, Florida, he had gone to the hospital with a heart attack. He died shortly upon arrival. That same week another man with the SAME name, had come to the hospital with a HEART ATTACK also. That man survived. My mother began receiving notices from the hospital that she owed money for my father's treatment. That made no sense because he was on Medicare and had supplemental insurance with that hospital. It took a few phone calls and then finally I thought to ask what the date of birth was for the person listed on our bill. It wasn't my father.
I tell you that story to share that this person who has listed you on their tree may well be doing it without malice. It could be a misunderstanding. If you approach it from the point of view that it is a misunderstanding, an error of entering dates that resulted in this problem, maybe you won't take it personally.
If this person's account is inactive (and they aren't paying), it's possible they cannot make changes or corrections. Is it possible that you could add a comment or a note to explain that it is not you? :)