Battery warranty replacement

Good afternoon!

My iPhone warranty will expire on July 21st and I would like to replace the battery, because the battery maximum capacity is 85% and the Battery Cycle count is 356. The percentage capacity is falling very fast and was 89% 1-2 weeks ago, so I think it will be very soon these 80%.

Also, the phone charges very quickly and is no longer convenient to use. As well as the brightness of the phone screen twitches, most likely due to battery fault. In Latvia, I am denied a warranty repair because I have a capacity of 85, but I believe that the phone battery has used disproportionately quickly during the year. In my opinion, that I am entitled to a warranty repair after one year of use.

I will waiting a response, thank you!