I bought 6 of these double-walled drinking glasses and now the last one is broken. I just cleaned it normally in the dishwasher and now it has water between the walls. I can't explain how the water got in there, it doesn't have a hole. The other 5 simply came out of the GS with a crack. The glasses are a total disaster. I haven't had the glasses for a year yet. Unfortunately, there's no receipt either.
Official Migros response
Hello Yolibolli, thank you very much for your contribution. These double-walled jars have a hole in the bottom during production, which is sealed by hand at the end. The hole is necessary for the production of the jars. Unfortunately, it can happen that the hole is not completely closed at the end of production. As a result, water collects between the two walls during the rinsing process, which can no longer be removed. The glasses are checked regularly to ensure our quality standards. We will inform the supplier of the circumstances and ask him to increase the checks. You will receive a message from us by e-mail shortly. Best regards, Yann