I purchased the Ultra Pro Rectangle. I used it on Sunday and it has burnt on the bottom. The oven was on 220 degrees and it has burnt. It says on the bottom of the dish that is can go into a oven up to 250degrees. I phoned tupperware and they do no replace this as it is burnt. So why is this not covered? it did not go over the desired stated temperature. Not happy. This is an expensive product that has not done what it should have. I am very disappointed to say the least that you spend over $150 and this is not covered. You would think that it would be covered. They should stop selling these as they just burn. All I am asking is for them to replace it.