Teacher, thanks for your question about removing the sales tax from an Adobe order. I see that you have already been in contact with our support team, and that case number ADB-27751888-Z7D1 is currently open and pending our response.
Please be aware that your request to remove sales tax is unusual. For the United States, the Sales tax is calculated at the time of purchase based on the state, and possibly county, where the individual is located. It is an automatic calculation and should not be confused with the request for Tax-exempt status listed at https://helpx.adobe.com/x-productkb/policy-pricing/place-tax-exempt-order.html.
I can tell you, as someone who lives in one of the few Sales tax-free states in the United States, I would expect that any adjustments for sales tax would be taken care of when the annual plan renews. If you moved in the middle of the plan, then no changes would be made until the next time a price adjustment was implemented.
You can use the process listed in https://helpx.adobe.com/x-productkb/policy-pricing/customer-support-portal.html to update your active support case, Teacher. Our team will be able to look into your specific circumstances in more detail.