Does Discord charge or have some type of contractual agreement with you? It does seem odd -- they must have some checking on addresses and personal information and what you posted just happens to match that regex.
And really, to your point—Discord is a general-purpose platform, not a technical platform or business platform, and its CS agents probably aren't equipped to deal with complex technical or business problems. It's kind of on OP for trying to use it that way.
CS agents are literally there so the rest of the company can avoid dealing with customers. If that means worse results for the customer then ire at the support agent makes sense. Don't take a job making the world worse if you don't like beeing blamed for that. Is the company forcing to make peoples life worse rather than better? Quit. Not always that easy, I know, but that's hardly the customer's fault either.
That said, group-chat-based support seems like the wrong solution in the first place - simply because Discord is a silo and they don’t make it easy to get your own data back out of it (this page is an infuriating read: https://support.discord.com/hc/en-us/articles/360004027692-R... ). Also, the fact that Discord themselves are using ZenDesk for their own support (instead of, y’know… using Discord) is another reason to not use Discord like this.
Orgs using Discord today are giving me the same vibes as those SaaS that thought they could do everything with only Redis and NodeJS (with no RDBMS in sight) - yes, it works and might even work very well in some cases, right up until it doesn’t and there’s no plan B.