Greetings!

I have bought xperia 5 ii and I am very disappointed. I am completely unhappy with the lack of security updates. There is already firmware version 58.0.A.28.25 with the security update for November 2020, but for the UK. And for RU only 58.0.A.21.1 out of the box. As a user, this tells me that the RU region has a low priority for Sony. I have bought expensive smartphone with a huge bunch of known and unpatched security vulnerabilities. And I am not getting updates. I want to return back this piece of sh... and get my money back. The store denies me, referring to the fact that this is a technically complex device and my claims do not relate to the functioning of the device. What can Sony offer me, how can I get my money back for a flagship with security vulnerabilities on board?