How can i convince my parents to let me get a coketiel.?

i really wnt 1 bad and we were going to move and she said the main reason i cant get one is becuase were going to move. but now were not going to move and thy still say no. i tries showing thm pictures of thm and stuff. tht im responsible. i showed thm i am bye taking care of my lizard and dog. i said i would buy all the stuff. and i would even bye the bird. i would buy every thing.i showed thm wht kind of bird i showed thm i could afford it but still no. ive been like asking thm since i was 6 but always no.and im am 11 now. i have enough still and i looked up how much every thing would cost but yaaa. still no.im getting really sad to T_T. please hlp me get one i really wnt one ive tried every thing tht came to mind even a report but no.sigh. please hlp.