DEMANDING MY REFUND

I booked a return ticket via eDreams and I tried several times to change my date and the connecting flight to no avail. When it was convenient for Kulula. Com to reschedule their flights, I was supposed to be in two flights at the same time. I called Kulula. Com but they couldn't help me and when I now apply for refund I am told I can't get. How, why? Is it because you treat me as a nonentity? Is it because you are the capitalist? On which basis are you refusing to refund me if you are the ones who changed your schedules without checking how it would affect your customer. I need my money back.