By ghosting them. Doubt this will help you though, since it's the most obvious option and I'm sure you thought of it and there are reasons why it isn't possible.
Right. I've blocked erotomania stalkers before and they somehow interpret it as a sign of my love for them, or at the very least rationalize it as being totally unrelated to me actually wanting them to stop fucking contacting me
What I've done was... uh... I guess it might be described as gradual ghosting? Reducing contact, frustrating them. But for various reasons, I don't think this would work for you at all.