SPAM - No option to stop marketing email?

At the start of last year, 2023, I enquired about the Rain services and decided not to use them. This year, I have been receiving marketing email from Rain. I unsubscribed but the email didn't stop. I tried calling the call centre and was advised to 'just mark it as Spam" or unsubscribe. So, Rain, you are telling me that, just because I made an enquiry ONCE, I will now have to deal with marketing email forever!