I don't know what to do or say. Apparently, you knew exactly what to do. It's not done on purpose. You may simply have different ideas, values, or expectations of each other. Thanking you in advance, Mahrah Dear Mahrah, You bring up a very interesting point about human nature, and the social pecking order.
Some people are very nice to others all the time, no matter what.
Others are more predatory and take advantage when they find people who let them get away with it. We test each other to find out our limits. When you were putting up with your friends' mis-behavior, they learned that you would tolerate switched plans, whether you were calling them on it or not. Once you backed off, they came after you - because they never wanted to hurt you in the first place. It's up to you, not your friends, to determine what best serves your purpose.