If you are referring to PAYG rates pretty much all of the operators in the UK have hiked the rates to make a monthly charge more appealing as it gives them recurring revenue friom a segment of customers that may not want to enter into a fixed term contract (like myself) or may have a poor or no credit history so would fail a credit check.
Yes, I found it a bit annoying too when they started to do that but I can see a reason for it.
