AIO or my Friends are making excuses?

I have a couple of friends in my PG. One is from my college(my graduation is complete and I am out to prepare for professional exam) and the other is younger than me. I have been here for almost 6 months now. I have tried making plans to go somewhere out with the girls. But when I ask, they say they don’t have money. And the very next day they are out with different people, or sometimes even together. What should I read out of it? This makes me feel excluded and lonely bc I don’t have other friends to go out with