Someone has attached the wrong father to me, how do I remove them?
I have to assume that your father's record in the FamilySearch FamilyTree is marked as Deceased. Otherwise nobody else would be able to see and modify it.
Furthermore, nobody else can see or modify the "attachment" of you to your father's record (i.e., the Parent Child Relationship) as that attachment is part of your living record and private space. This means that nobody has attached the wrong father to you. Something else happened.
Based on this, one of two things (or both) happened:
You need to look at the Change History for the PID that is currently attached as your father to see what happened to it and who made the changes. When looking at the person record for yourself, what is the PID of the record being shown as your father?