Hey @Jillian Starr23! I'm sorry for the trouble! Thanks for letting us know what you've already tried to resolve this.
Please note that archiving a form will not prevent it from being able to be signed up to, if it's still embedded on your site somewhere.
The only way to remove it from your site would be to remove its embed code from whichever page(s) its on. Unfortunately we don't have a way to automatically detect which pages a form is embedded on :( The code would have to be manually located & removed. (Another place to check that you didn't mention might be under 'Widgets', or anywhere else your site's theme allows you to add custom embed codes.)
That said, as a first step, to immediately stop that Sequence from sending any more emails, go to the settings for it and uncheck all the sending days — that'll prevent any more emails from going out from it!
Then, I'd recommend reaching out to our team at help@convertkit.com24 (or via the in-app messenger in your account) with a description of the issue (what you posted here is great, but please also specify the names of the form & sequence in your account. Some example subscribers affected would help too!).
One of our Product Specialists will be able to help ensure that form is 'disconnected' from the older offer and also provide insight as to how to prevent this in the future! (But please note that we are limited in how much we can assist in removing the older form from your site, as we can't do that from within ConvertKit. But we'll definitely help as much as we can from our end, so feel free to include any questions you have!)