I've very rarely ever been flat out rejected, the only time it has happened to me was when I'd approach women at a bar, which I find interesting because I would never bother with them normally.
However, I have been rejected by other much more annoying and frustrating means.
I've gotten numbers which lead to absolutely nothing, I don't think this is all that rare or unusual but it does happen. Most of the time it leads to just one or two texts and then nothing. However, a couple times I've had them engage me to quite a high degree through text, actually making plans and all that but only to later flake. In the case of the ones who just don't or barely reply, I just delete the number. However, with the ones that are pseudo leading me on I usually just tell them I have too much going on in my life and have no desire for a text buddy and then I delete the number. I do this to call them out on their rude and childlike behavior, hoping that maybe they'll learn some common decency and social skills.
I've had women approach me and after some interaction I'll ask them out and they respond with "I have a boyfriend". However, I've had these same women go out of their way to approach me again later on, which again has never resulted in something positive. This is either one of two things, she legitimately has a boyfriend and finds my attention flattering and is actually attracted or she is purely an attention ***** and has literally 0 interest in me. I've had both scenarios happen, with the former there is a mutual interest but due to her not being available it just wastes a lot of time and energy. With the latter I find this to show quite a bit about this woman's character, though I can't quite figure out if the one's like this are aware of their behavior and just don't care or if they are simply very clueless.
I've had women approach ME and ask ME out only to later cancel the date and ghost. We would literally face to face make a plan and later that day they say how something came up and asked for a different day. The first time I ever had that happen to me I just asked for a reschedule, as in my mind it made literally no sense why a woman would go through all of that if she was just going to flake out and ghost me. Women like this are essentially attention *****s, like the example I gave above, they just go about it in a different way. However, I feel some of them do this to have a lineup of guys, in order to be able to pick and choose the best candidate without closing the door completely on other suitors.
With all of this said, I don't approach women all that often, it's actually been at least a month or two since the last time I have done so, and to be quite honest I'm not all that interested in doing so.