Excessive Increase in Premiums

I had insured my house contents with Auto & General for about the last 13 years. In 2023 they contacted me offering an attractive premiums for both my house contents and structure. On the fist anniversary of my taking up that offer, they increased the valuation of my house contents by 8%, the excess applicable by 33% and the premiums by over 150%. This seems more like the classic bait-and-switch con than an ethical business practise. When I phoned them they had the gall to compliment me on my handling of the policies over the years before informing me that they could do nothing about my premium increase. Buyer beware!