Xiaomi Refused to Let Me Change the Color of the Gift Watch

I wanted to change the color of the watch given with the 2 phones I bought from Antalya Özdilek branch because I did not like the color, but it was said that no change could be made because the package was opened, I talked to the branch and said that I had the right of withdrawal within 15 days, and the branch official serhat jobs said that you cannot make a return according to your head. Shamelessly told me that there is this in the laws, when we buy over the internet, all kinds of exchanges or returns are made, I wondered, I talked to Xiaomi Turkey representatives and they said that the store decides, the absurdity starts here, how do they decide how you are not Xiaomi, do you have no rules or do you not follow the law? I only want to change the color of the gift watch, nothing extra, I regret buying the products, I am waiting to see what will happen to me in the future and what they will not solve.