How to convince my dad into letting me get a ferret?

Prove to him that u can take care of it , and that u WILL pay for them because they r expensive and hard work but they are soooo amazing, u rlly shouldn't keep asking, and maybe he doesn't think u are responsible. U need to be rlly responsive and have the time and space for a ferret(: I suggest that u buy the book Ferrets for Dummies and read it cover to cover!! Please if u do get one take really good care of it!!