Yes, you can ask that they a) explain exactly where they have got this extra amount from and b) reconsider. If no joy you can make a formal complaint to the IP which can then be escalated to their regulatory body if needs be. Out of curiosity was the review conducted by Ebenegate ? Thanks for that,...

Is it possible to appeal an annual review? I’m earning a bit less than in the previous years review and outgoings are slightly higher, yet they have increased my monthly payments by £20.
Checked my P60 (which they have a copy of) and there’s a difference of over £2,500.