Best Buy-Arliington Heights,IL unreliable,deceptive,uncaring,defensive,not standing behind merchandise sold Arlington Heights, Illinois

I bought a cheap wired mouse 3 weeks prior to today at the Arlington Heights,IL location. I didn't think of keeping the receipt as it was only $20 and they logged my info in the system. Today my mouse didn't function properly so I called the store. I spoke with a pleasant gentleman,whom told me not to worry about the receipt as they could look it via the credit card. So I went it, and of course to my misfortune,they couldn't locate the mouse being purchased. I admit, I probably should have kept the receipt but I figured it could be looked up via credit card. They refused to return it and basically I was out of luck. I found them to be very cool,unreceptive and not standing up to their merchandise they sell. I think for $20 they could have offered me a store credit. It does show on my history (as I have bought warranties on products over the years) that I have spent a significant amount of money as their stores.
In the Springfield,Il location I was told by a rep that if if I bought a potential game and I didn't like it,I could return it for a refund. This was not the case, when I called up the store a day later with the rep's name. There only remedy was offering me 10% off a $20 game (which doesn't work properly.) I know rep's are human but the store should stand behind what is being told by the reps. I have worked retail before, and if I misquoted something, I stood behind what I originally said. Though this was seldom as I gained through knowledge of what I was selling.
In the end, I bought another mouse at this Best Buy as they have a decent selection and the time of night it was,being close to a holiday weekend. I will keep my receipts from now on but I will try not to purchase items from Best Buy anymore. They could have accommodated me but they chose not too. Shame on you, Best Buy, for your greediness and deceptive selling practices. You should stand behind what you sell and not be so restrictive on returns.

Thanks