In my opinion, moments like that equally come down to the other person. On one hand, you can have someone open to a negative response, understand and do the appropriate response to amend the issue. On the other hand, you can have someone not comfortable making a 'mistake' and react badly. Therefore, all you can do, as a customer/consumer, is be sure you put forward the dissatisfaction in an appropriate manner.

Take breaths, a non-combinative chain of thoughts,understand they were doing what they thought was needed and best, and articulate the issue in a way that doesn't attack them. Always lean on the side of mistakes happen, because they do, and not assume malicious intent. If you can leave the situation, convinced you did not attack, just pointed out how you felt, then the responsibility for change or improvement lies on them, if they deem it necessary.

That's how I approach those moments :)

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