Instruct: Classify Amazon reviews into positive or negative sentiment
Query: worse customer service I ever experienced

Bosch has the worst service department I have ever dealt with as a consumer. They refused to return any emails or phone calls after one of their tankless water heaters blew out our plumbing.Don't get me wrong, tankless water heaters are fantastic, but don't buy one from this company unless you plan to be on your own if anything goes wrong.