Sorry, Genesis, but sometimes shit happens.
I was married in '75, divorced in '76 and still getting back together, breaking up and not making it in '79, when we both seemd to agree that it will never work out. We finally split for the last time. It seemed.
We went our own ways. Finally.
Two years later she came back around, messed up my then current relationship. I was not kind to her. It was way over. Every year or so, it kept happening. She would just show up and want to start again were we last had fun.
Until finally, in the '90s, I was happily married to my current wife, enough time had passed, I had quit worrying abour her ever bothering me anymore.
Then, in '04, sitting with my wife and two kids, enjoying a movie (probably Disney) one peaceful Sunday afternoon, out of the fucking blue, she found me again and called.
I tried again to let her know we are done forever.
My wife is the strongest woman I have ever met and she handled the upsets like a warrior would. Gave me a lot of tongue in cheek snipe for a few days, but she knows I'm hers. Growing old together, now.
I haven't heard from my ex-wife since, but it took a long while. Later I found out that she had called my mother and tried to tell her some kind of heart wrenching bullshit to try to get her to give up my info, again.
I'm not talking about an easy path, here, but you must be consistent with what you do and say and after some time they will eventually get the message. Consistency is the key point!
I just hope it doesn't take you twenty five more years!
But, sometimes shit happens, even to good people.