Mine has been getting cheaper year by year
I had a hell of a time with Vodafone a couple of years ago, triple billed me 3 months in a row and had to get my bank to get the money back via DD guarantee.
Eventually went to 3 on a monthly sim only, 20 gig, u/l calls and texts for 25 quid
At renewal went to 20 quid
latest renewal 30 gig u/l callls and texts was 18 quid with full tethering