You are correct, which is why I didn't pursue the matter. They can keep my money, they've lost a customer.

They are providing a SERVICE. I was not using the service, I didn't need it. The mistake might have been mine (assuming it wasn't a dark pattern or sketchy design) but they had a choice: keep my money and tell me to go fuck myself (which they did) or refund my money at no cost to them. This wasn't a box of goods that they would have to take back and reinventory.

I would have purchased the lower tier of service (which I explained to the rep) and continued to use their services, and I would have been telling you about how they were reasonable and I am a happy customer.

I had already invested significant effort in moving my email over, it was a pain to shift back, but if Proton's answer to a simple problem is "fuck you, we've got ours.", I'll pass. I spent a lot of time on their 'pick a paid service" page because I was going to pay for one of their lower tiers, I just hadn't decided which one.