In March 2009 I paid £249.58 for a window regulator (the control that operates a car window) for the near-side rear window on my Renault Megane. In January 2011 I paid £56.10 for the off-side rear window to have a new regulator fitted. The reason it was much less was that the second bill included a £140.25 goodwill reduction.

When I queried the rates Renault UK told me the gesture only came into force in May 2009, and so the first one I bought fell outside of the "goodwill" period. It admitted there is a problem with the part and agreed it was silly it would pay for one and not the other because I was unlucky enough for it to have broken too soon. Can I get my money back for the first repair? CB, Hove, East Sussex

The goodwill reduction Renault referred to was a commercial gesture it made in 2010 after it acknowledged the window regulators on some models were faulty. This entitled the owner to 75% off the repair cost. So it wasn't goodwill Renault was showing but a reimbursement you and many customers were entitled to.

When Renault was asked why it had not reimbursed you for the earlier repair it explained that your car was outside its warranty period and that the gesture only came into place after your first repair. The warranty period part is a red herring as this is irrelevant when the manufacturer has confirmed the parts were faulty. And it was hardly your fault your initial repairs were carried out before Renault acknowledged there was a fault. Renault has now changed its mind. It is reimbursing you for £187.18 – 75% of the cost of the repairs.

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