Excuses pour produits endommagés (4)

Dear [Mr or Mrs or Sirs], We acknowledge receipt of your letter [date] in which you inform us that [produits] delivered on [date] have developped [faults]. We are surprised and very sorry for this, as all our products are subject to strict testing and checking procedures before being delivered. We suppose that [causes], your complaint being the only one that we have ever received. Your suggestion seems to be the best way to resolve the matter and we shall immediately [action]. You should receive the [produits de remplacement] before [date]. We apologize for the inconvenience it has caused to you, and hope that this will not spoil our good commercial relationship. We do everything necessary so that it will not happen again and shall do all our best to give you satisfaction in the future. We are looking forward your orders that will always keep all our attention. Yours sincerely [votre nom] [votre fonction]