In Nov. or Dec. 2010 I bought a new Interplak "waterpick" dental hygiene appliance. I always go online and register my product promptly anytime I buy or get as a gift, as I did this time. I also save my receipts but this time I can't find this one. The product has stopped working and I called the Conair Company customer service line and was asked; do you have the sales receipt"? So I tried to pull up copies of my Mastercard receipts for Nov./Dec. 2010 but it's doubtful that they will be available from the retailer of Mastercard. This is why I faithfully go online and register my purchases, logging the store, date of sale, price, etc. so that I can "trust" the manufacturer to stand behind their products, and in this case, with Conair, I'm getting screwed. They should either have a database that is reliable, reference-able, and customer accessable, or they should just publish a policy of " keep copies of everything, as given the slightest chance to disavow any responsibility for the quality of our products, we will pounce on it, and thus screw our customers".