A final update.
I've been down to Endesa for a 3rd time to ask why I was issued & paid for 10 bills at once. These are revised bills for the past 12 mths showing usage.
My account shows that I owe nothing & the €5,000 bill has been anulled. There was a discrepency then of some 20,000 units still. The lady in the office then printed off past facturas to see what was happening & to her and my suprise Endesa have written these units off ..... I have the factura which shows this. Needless to say I won't be sending back any payments taken & I'll be keeping my head down until I have it in writting that the case is closed as I've ended up paying considerabley less tha nthe big bill.
I hope that this is the end of it, complaining certainly helped in this case.
Good Luck to all with problems.
PV
p.s. please spare a thought for the poor workers in the Endesa office, it's not thier fault that the company they work for keeps throwing up problems for us the consumer & that they are understaffed, the info on the computer system isn't good and it's only through smiling & the lady digging through the data & wanting to help that hopefully I can draw a line under this.