I'm not tarring anybody. I've been on my dating website account and he is a very nice person but sadly not for me but he won't accept that I don't want to meet or swap numbers
oh, online, nobody's normal online. He may not even be male. Is there some sort of button you can click that will deliver an electric shock through his keyboard?
You could try "shaming him". I've done that a few times. You say something like "It is not going to work. I have said I don't want to meet/swap numbers and you won't listen. It is important to me that the man I meet listens. You don't. So flump off".
So not completely nice then as he won't take no for an answer. From a male viewpoint 'no' is the default reply of a female thus giving the male an opportunity to think up all kinds of bribes and inducements in order for the reply to change to 'maybe' or 'perhaps' or even 'yes please'. You on the other hand could qualify 'no' with 'not in a million years' as a hint that you will not change your mind.