Yes? You bought OW1, played it for 6 years. Now, you can either play OW2, or just quit the game? Sounds perfectly reasonable to me.
Or wait, you want a refund for OW1? That would be cool if that was how business worked, lol. Use their product for 6 years, then just get your money back. I’d love to go walk into a movie theater and be like, “hey, I saw the movie, can I have my money back now.”