I had a rough time very early on in my training which has cost me atleast £1500 and still feel pretty bitter about it to be honest. But don't let a company ruin the rest of your training, as said above, make sure that your invoices and logbook tally to the penny. If they don't then go through everything with a fine tooth comb and find out why not.
Flight schools are very quick to put prices up but extremely slow to bring them back down again. Although to be honest at the moment I would rather my school builds up a bit of fat to live off whilst times are tough than they charge me the a few quid less per hour and go under half way through my IR!