Canary42 has failed to add on the VAT (at 5%) but, even so, I can't get to the figure which is on your bill. You appeared to have been charged £940.89+VAT, which is still more than Canary42 has correctly calculated.
The price per unit is definitely correct:
http://www.edfenergy....ard-tariffs-25-07.pdf
I'm surprised that you've been charged for 903 kWh at the higher rate. Your bill covers 138 days and the number of KWh at that rate should be calculated pro rata to 2680 per year. That means that you should have paid for 1013 KWh at the higher rate.
You've told us the final meter reading (2541) but not given us the previous one. It would help if you could supply it.
Chris