How do you get rid of someone?

No, I'm not talking about murder or anything so drastic. I'm just talking about your run of the mill, "I don't really want to know you anymore" kind of thing.

Let me explain.

There's this girl that I was friends with for a while... until I started to realize she was bat-shit crazy. For a while, the merit of her crazy relationship stories was enough to keep me interested, but I honestly didn't enjoy spending time with her. Now that she's suddenly married, I just really don't have any interest, you know? I know it's rude and mean of me to say, but I don't want to be this person's friend anymore. There's just too much going on in my life right now and in my head to worry about her.

Frankly, she annoys me. At restaurants, she's always rude to the servers, but when we get together, it's usually for lunch or something so I have to put up with it. Even last time I saw her when we went shopping, she got a bit of an attitude with one of the sales people. It doesn't seem to occur to her to be nice.

I hate to just call her up and say, I'm sorry but I don't want to know you anymore, but what can I do? She calls me all the time! And I just don't pick up because I'm busy and I don't want to hear her whining about me never answering the phone. I honestly thought that after a few weeks of me not answering the phone and not calling her back, she would just sort of get the hint... but it's not happening! She's just becoming more persistent! Yesterday, she called me at 7:30 am. Seriously? Then again at 10:30. Then she texted me. But I know that if I answer, she'll just rag me about not being available, and I still won't have the nerve to tell her I don't want to really talk to her anymore, so the cycle will continue. Does anyone have any suggestions here? Besides just being brutally honest?

I hate confrontations, but I guess I need to tell her how I feel. Or just put up with it. Annoying.