health insurance

Husband’s company informed us that their HMO doesn’t cover norcal (they are in socal) a month after we enrolled and selected benefits. They sent us an HSA credit card thing. What is going on?

Signed up for health insurance on my partner’s plan through her employer, terminated it after we were billed 3x as much as we understood it to cost. Now outside of open enrollment and having a hard time navigating this weird situation.