It is unfortunate that some people cannot take no for an answer. I refer to these people as 'reality-impaired' as they quite often live in thier own little worlds and have a complete disregard for anything that differs from thier own wants.
Twilight, this is not a failing of yours, as you are the novice here seeking wisdom so that you can expand, and grow in a new way.
Please do not let the failures of a would-be online Dom in any way tarnish what you may find in a fulfilling online relationship. What you can gain is worth the risks of having some imbecile call you names.
Also, you may feel more at ease in the future if you distance yourself a bit and have an additional layer of anonymoninity in place. Try setting up an extra email account associated with whatever IM program you use (yahoo works well for this as does hotmail). By doing this you only have to worry about talking to them when you want to, and if they get annoyingly persistant you can abandon the account and not have to worry about them.