We have been coming to Cozumel before Mega opened so have always had a nostalgic feeling for Chedraui. Last year I returned laundry detergent because they had charged me 3500 pesos instead of 350. It wasn't a problem getting a refund but it made me pay more attention to my receipt.
This time I bought a thermometer that had no mercury. We had a good laugh trying to take a temperature that was never going anywhere. I tried to return or exchange the next day with the original packaging and receipt. We were first sent to the pharmacy area where we had purchased only to be told "NO, NO, NO!" with vigorous finger shaking. We then went to customer service where they looked at it shrugged and said no return. I said an exchange would be fine but was told no. I gave up and left with no refund, no thermometer and no desire to return.
Maybe if I was a local I would have been treated differently but from now on I will do all of my grocery shopping at Mega. Mega is, in my opinion, cleaner, better stocked and more customer oriented to non locals. I am sad to give up on Chadraui, and will miss their donuts, but have lost confidence in them.