Do i deserve to get a dog?

Im 13 (i think) and i really want a dog. my mother doesn't want one because of the droppings. and my father always thinks that a pet can just be fully trained and would do anything he wants. how do i know? well it happened before. after lots of weeks asking for one they got one for me. i was so happy but in a few days my mother kicked him out. i was stupid and little at that time and didn't even try to stop her, i just sat there smiling like a ********* watching my only dog getting kicked out (i don't mean really kicked with the shoe i mean taken back to the store). i waited a few years and know its time, next month will be the 2nd "my dog getting kicked out" anniversary. but the problem is...... DO I DESERVE A DOG? i know how can i convince my parents but do i deserve one. i try my best to do good in school (not just for the dog) and i listen to what ever they tell me (sometimes) and - unlike lots of people - i don't have any other pet but a little Innocent bird, which is no problem AT ALL to my parents. sooooooooooo do i deserve to get what i have always dreamt of since years? if not how can i improve?