Face Meets palm, and the two fingered salute to EDF

So I have a prepayment meter for paying my electricity. I had this installed about a year ago as I was concerned about falling into debt when my Access course started and my salary fell by about £1000 per month. So anyway the last year has been uneventful with this electric meter. Until a month ago when my key for topping up started to develop problems registering. I duly notified EDF who said quite nicely they would send me a new one out within the week. Four weeks and ten calls later the key still hasn't arrived. And this morning my last top up for electricity has run out and the key has finally given up the ghost and wont register in the top up machines or my meter. This means that I have no electricity i cant use the emergency function as the key is not working and EDFs response well send someone Thursday. Unless I pay the £30 call out charge today! I tried explaining to them that I don't get paid until Friday and they are the ones in error as they still have not sent me the requested key. Two fingered salute is due to EDF I say!!