So does your response mean (1) "take it easy on Namecheap because this kind of bait-and-switch is common among registrars", or (2) "take it easy on Namecheap because it was unintentional incompetence"?
I'm saying take it easy on Namecheap because it's out of their control, and would have happened regardless of the registrar you used for that particular domain. The incompetence is on the part of the registry, for not having properly identified the given domain as premium until post-registration.
> I'm saying take it easy on Namecheap because it's out of their control…
If we assume that Namecheap is incapable of malice, then it means Namecheap's systems and/or processes are broken. (Registry agreements don't allow registries to retroactively reclassify domains as "premium".)