How to get my parents to be nice to me and get what I want?

Last week i did not go horse riding as i slept cause i came back from camp, but asked my parents to wake me up half an hour before - they did not. My mum promised me that I could go this week and that she would compensate with another riding lesson. This did not happen and so I really thought that I would go this week. My older sister had been on a trip and was supposed to come back at the time of my riding lesson. I told my mum and dad that I would see her afterwards and that if they were going to pick her up I could make my own way there or that I could go earlier than usual and help. They called me selfish. Whilst my mum and dad were out buying jodphurs for me for my birthday (I mean, what is the point if i'm never going to go horse riding again) they got a text from the school saying that they could get an earlier ferry and would be back around 11.15am so they went to the school, but my sisters coach had broken down and they were waiting for a mechanic to fix it, so they would be back later but they did not know when. I received a call from a close family friend saying that if i needed a lift there she could give me one. My mum came back 10 minutes before we usually leave to go, which really annoyed me but i did not show it. I was all ready to go horse riding. She then told me that I couldn't go because she did not know what time my sister would take me so I told her that our friend had rang and offered me a lift, still she said I could not go and I was running out of time so I rung our friend up to speak to my mum, my mum shouted at me and I was getting really frustrated and starting shouting at her. She said down the phone to the friend that I was not going to go. I was crying as I still could not go and was probably going to be late. She then said that i'm not going to go next week - unfair, much? It was her fault I was crying. I adore horse riding + horses and if I dont do what she asks she says, right, your not going horse riding now! I do try very hard and it just really stresses me out when she does this. I get really down as well. How can I get her to be less strict and let me do what I want - I'm 17 now and she won't let me!!