After exchanging #s, only to never call, what if you see that person again and they ask why? What do you say??

It's awkward when I met a guy and exchange phone #s (mine or his) knowing that I may not call him soon or at all. Sometimes in the phone # exchange process, I get caught up in the fun idea of meeting someone new and forget that I'm just not a phone person at all ( I believe telephone convos are uncomfortable and build more anxiety for the conversation to keep going), but regardless of the communication type, I'm bad with keeping in touch with people period. I have a busy life. Sometimes, I tell guys that and they still give me their #/ ask for my phone # anyway. I never get around to calling them or even wanting to call them. A few days or weeks after, I see the guy I was SUPPOSED to call or SUPPOSED to have answered his call and didn't. Of course, I get silence/ the cold-shoulder from them or I get the questions: "What happened?" or "Why didn't you call/ pick up the phone?" What do I say in these awkward situations? This is a bad habit of mine I no longer want to continue.

Apologize and tell them the truth, that you're bad with returning calls and keeping in touch with people. And you're not a telephone person. It they can't accept that then that's their problem.

If you no longer wish to continue this bad habit, then it's time to stop accepting phone numbers. Despite that they're persistent in offering their number, don't take it. And if they do call you, take the call and tell them you're not interested. It's the nicest thing you can do for them and maybe then they can call someone who's interested in callling them.