Promises? GTFO!

ok now I'm really pissed off...REALLY...
My parents promised me -PROMISED ME- they'd do what they could to help me training. They would have helped me building obstacles and so on...
Today I asked them if I could put a SINGLE wooden board in the garden to simulate the Spider Flip. ONE, not two, not the entire thing, ONE. I asked them why, they said it wouldn't have worked. I explained them that it would have worked, and asked my father if I could. Ya know what he told me? Ya know what? " I don't want a stupid wooden board in my garden".

First: YOUR garden? YOUR??? I live here too, yo? Have you noticed that?
Second: You put whatever you wanted in that garden, you put a horrible stone floor on a good part of it, I told you I didn't like it but I didn't say anything more. You put in a horrible metal thing you call "gazebo" in it, I told you I didn't like it but didn't say anything more. I let you do whatever you wanted of MY bedroom, and now I can't put a single friggin WOODEN BOARD in OUR garden?
Third: you...YOU PROMISED you would have helped me, you would have done whatever you could to help me!
When I promise you something you tell me a promise is a promise and I should never give it up. Yeah, I really do believe you.