I read an excellent book called "The Gift Of Fear" by Gavin DeBecker. He is a well-known security specialist, has done body guarding for celebrities, worked with the Secret Service etc. I suggest you purchase it. It has a chapter involving how to deal with stalkers that is extremely informative...right on the money. The biggest piece of advice he gives is DO NOT HAVE ANY FURTHER CONTACT WITH A STALKER,NO MATTER WHAT!
You have told him to leave you alone. Do not speak with him again. Each time you speak with him, in his deranged little mind he's sayinbg"she must feel something for me or she wouldn't be speaking to me". Alarm your home, make it seem like when you go to WDW that soemone is there(you may want to hire a housesitter), keep your windows locked and blinds drawn closed at night, be very aware of yor surroundings, go to the police immediately and report it...you want a paper trail, call the hpone company and tap your phone, keep any answering machine messages.
This person is a criminal. Treat him like one.