If you want to appeal your council tax band, you must continue to pay your instalments until you receive notification otherwise. If you later discover you've overpaid, you'll be entitled to a refund. For detailed information on how to appeal, you can check the Valuation Office Agency’s website.
Here are some resources for your appeal process:
If you have further questions about your bill, you can contact the Council Tax team directly by logging into your council tax account here.