Animal anti-cruelty? more like profitable business like every other business

i found a dog over a week ago i claimed it after finding it twice in a busy area going through garbage. I needed to get her some medical attention and shots so i took her to the animal anti cruelty league who now want me to wait 2 weeks and pay an adoption fee of R850 for a dog i already claimed and gave a home. these people are not anti cruelty they are just out to make money like every other business. i dont see why i must pay adoption fees i already feel i own because i claimed her as she was on the street going through garbage.. why must i pay for a dog i found on the street. If you found a R200 note on the street you wouldnt put that up for adoption. I want to give her a good home and i feel i own her so why must i pay for her now ?