Me and My Girlfriend

Ok so I recently broke up with my girlfriend of six months. I decided to explain what went down and see what my fellow tempers think. So where to start....Ok I was at church waiting for bible study to start and we were talking. We got on the subject of food and I started comparing her church overall to all the food I've tasted. I basically said her church's cooking was medicore and ok. It was good but I'd had better. She took offense to this and told me to stop talking and I sound stupid. Totally unaware that I offended her, I asked why'd she say that to me. She tells me nothing. She believes that she can say anything and just get away with it. She knows that doesn't fly with me. So we begin to argue and in the argument she tells me I offended her, but note I'm voicing my own opinion. So I told her all she had to say (versus what she said) was that I was being a little to harsh cause as I told her it is possible to offend someone and not know it. So we countinue to argue and she begun to "act/say stupid" so I got mad and told her to shut the hell up. I leave, eat, and clam down. I call her back. I begin talking in a nice tone and she ignores me. So I was like why are you ignoring me. Her response was that I was mad so she didn't want to talk. I was no longer mad until she countinued to act stupid. Then she hangs up in my face and when I call back she says "i had to switch phone but I didn't feel like telling you". That was my last straw. Note that once I after I clamed down the 1st time and called her back I apologized for getting upset and telling her to shut up. So basically I'm trying to resolve the issues, finding better ways to handle things so this wouldn't happen again, being mature and she is over on the other line saying whatever, doing whatever (thinking she can get away with it and that what she says is end of story), being immature, getting smart with me and everything. So after she went to her bible study, I tought about and we are no longer together. So voice your opinion on this tempers.