>>2023
Protip:
Never try that in Bavaria. Things work differently here and the customer isn't king. The state is king, we are mere serfs. And if serfs try to act up there will be consequences. So demanding to speak to a 'manager' in any sort of store here will get you some odd looks and maybe laughs. Managers become managers so they don't have to deal with shitty customers and they won't. The only one a cashier will eventually call is police and Bavarian police have very low tolerance to troublemakers acting up. At best you’ll spend the night in a prison cell, if you continue to demand ‘rights’ it’s the psych ward for you. No release schedule.

Everyone in Bavaria knows the case of Gustl Mollath who was an autistic oddball who rubbed authorities the wrong way in a divorce battle with his wife.
https://en.wikipedia.org/wiki/Gustl_Mollath

Though he was right in principle he made a scene and was committed to a high-security psychiatric hospital for 5 years, had all human rights and possessions stripped and was only reluctantly released upon massive public pressure after his case ended up in the news. Otherwise he would have died in a padded cell. That was 10 years ago. So don’t. We have very good EU consumer rights and you will get your money back if you submit the proper paperwork. But going full Karen in a store and especially around authorities is not advised.