I got a renewal quote of £103 from the RAC this week (Roadside, Recovery and Accident Care). Last year it was £82 and I haven't called them out. I rang the RAC to tell them I wasn't happy and I was going to look at leaving them and joining the AA. After giving me some waffle about other people calling them out and rising fuel prices, the chap just chopped off £21 and offered to reduce my renewal to £82! I was happy with that and I've stayed with them.
It might be worth ringing Green Flag Denis and telling them much the same.