There is clearly a problem with the lids for this family of products. There are a great number of consistently bad reviews about them. Either: 1. Some of your lids were not made to specification. Those of us who have cracked and warped examples have sorted them for you, or 2. All of your lids were not made to specification and the people who haven't had problems yet, will. In either case you are responsible for replacements. No fast shuffle about receipts just bring them back to the store for a refund. I assure you you have lost my business thanks to this product. Like the upper management at VW that has just resigned your corporate house needs cleaned. I expect no response as that would be totally consistent with your lack of interest in your consumer's welfare. By the way, if you consider this inflammatory you don't want to hear the truth.