Klaviyo: Email Marketing & SMS

in sort of a nightmare situation now with adding our domain email and changing DNS records. all of our emails are landing in spam. Klaviyo said it was because we lost the confidence of the consumer... not true. this all happened in a week as we were trying to change our email.
support is zero help. we said we would need to switch email companies as being without our email marketing for weeks would seriously impair our business, they simply say... sorry to lose you. we literally spent 1-2K a month...switching to omnisend or finding another partner