I wouldn't give her the same spiel about only wanting a relationship again. She no doubt knows that by now. It blows my mind but 4 years later you are still plan b. She lied to you about not dating anymore and apparently hasn't given up hope that there is something better out there.
I would just respond to her texts with short replies and rebuff all her requests to get together with "sorry I have plans". Make it so she asks you what is wrong. Then tell her I clearly told you I am not interested in being friends and then wait for her response to that statement.
