Worst Values, don't even stick to their own words

Miway sent me an annual review letter on 3 November 2022 saying my premium will increase to R1244.30 from November 2022; however, to my surprise, just 3 weeks later on 25 November 2022, a day before the new premium is supposed to go off they send another 'annual review letter' now with a premium of R1543.16.

How many times a year does this 'annual review' happen; now they refuse to stick to the initial letter saying it was a mistake, why must I pay for their mistake? The least they can do is own up to their mistake and make another adjustment in November 2023, not send 2 'annual' reviews increasing premiums in just weeks within each other.