I had a similar experience to @Sallycinammonbangsthedruminthe
This was an ad from lonely hearts column in newspaper, i answered an ad and we swapped numbers, swapped texts for a couple of weeks, got on quite well, so when he suggested meeting for film/drinks i said yes
He was polite & friendly enough etc, but there was just no spark & i got an odd vibe from him
The next day i text him to say thanks for the film etc but that didn't think it would be a good idea to meet up again as i didn't think we were suited, he begged for days for me to change my mind, but i stayed firm and refused (politely, if a little blunt) he then kept threatening to kill himself, i just ignored him at that point, and after i ignored a few texts he gave up
Bout 3 weeks later i got a text from his number, but the person said they were a friend of my date and that he had slashed his wrists the week before all cos of me and had bled to death all alone in the bath
I didn't believe a word of it and just told the person to go away and leave me alone, I didn't get a reply so thought nothing more of it & deleted the number
After about a month my phone rang, didn't recognise the number and answered it, only to have my date start speaking to me! He apologised about the suicide threats and pretending to be his own friend to try and get at me, and asked if he could take me away for the weekend to apologise 
I told him to fuck off and hung up, and then called my provider and got my number changed