British Gas just increased my monthly DD from £67.50 to £112, despite the fact I am already in credit. I specifically set my DD to £67.50 when I took out the contract as I worked out how much energy I usually use based on the last couple of years and divided it by 12. This has worked out perfectly so far in terms of what I am paying and how much I am in credit by etc. Obviously now they don't let you reduce it back using the online service and its virtually impossible to speak to anyone at an energy firm at the moment.