I've been with Economy Energy for both Gas and Electricity since July of 2017. I was pleased to note that since then there have been no price increases. Their website can be a bit awkward and inputting meter readings leads to more doubt than certainty, but they sort it out eventually and everything works quite well. Then today they sent a text saying that their tariffs (which, whimsically, they refer to as "my tariffs") are changing as of 31 July 2018. Really? A rift in the space time or just some 16 year old work experience playing with their computer? I phoned their helpline. 4 minutes of options and pressing keys later they say they are experiencing very high call rate and maybe it would be better if I called the another day? Maybe they mean Sunday when they are shut.
I run a spreadsheet on which I record all meter readings since 2010 I have to change the rates from time to time but it is generally accurate to within a few pence. I wonder why I can do it on clockwork excel and they all seem to muck it up on whatever they use.