When mid-contract price rises were first allowed by Ofcom, they were percentage-based thus lower-priced plans had a lower increase. Then the inflation-crisis hit and price-rises breached double-figures, causing mass complaints.
There has been a general trend across the industry since then, towards "simplicity" that is best achieved by fixed-price increases, also achieving the price certainty over a 2year minimum-term that consumers generally want.
The negative-side of fixed-price increases is that they tend to be a higher-percentage on lower-priced plans, as in your case. Whatever the industry or individual operators do, is likely to cause upset somewhere. There are a handful of providers out there who advertise fixed-prices across 24months, but they may have other drawbacks in other areas.
