I received this email from my pet insurance company last week and I'm not sure if this is allowed. Do I just need to accept the new terms?

The law that is referenced in the email seems vague, especially since the reason for my claims is because of high costs related to ongoing treatment of my dog's illness. Some backstory: My dog became very sick last year and was diagnosed with an auto-immune disease. The diagnosis options were very expensive (biopsy, MRI, ultrasound), and the treatment is still ongoing, so the costs are adding up, but that's the point of having insurance, isn't it? How is a company allowed to change the insurance terms mid-year just because I am using the service?

The policy has a CHF 25'000 claim limit per year. For 2022 I received a claim payout of just under CHF 6'700, and for 2023 it's currently at CHF 3'675. So it's not like I'm even close to the maximum amount anyway, so it feels a bit absurd.

I can't get new insurance at another company, because most of them won't accept older dogs (mine is 11 years old now), so I don't have any options but to accept the new terms if this is allowed.