All relationships are TRAINED BEHAVIOR. From the relationship you have with your boss, coworkers, mother, father, friends, dog, etc.
YOU TRAIN PEOPLE AS TO HOW THEY CAN TREAT YOU.
If you allow this behavior, it will continue, AND you will lose respect with them and the fact they now know they can disrespect you with impunity and without consequences, they will when they see fit and it is advantageous to them. Draw a line in the sand. Get to the bottom of that BS. If you can work it out, please do. If not, get new friends and be friendless until you do. But to put it in colloquial terms, by all means, NEVER let anyone treat you like a dog or a punk ass b*tch.
Nobody has to kiss your ass, but they can be civil and text you regarding plans they made with you. Accept no less, or you'll be on the D list the rest of your life with respect to that group of "friends."