In most cases, you should contact your hosting provider for support with topics such as cPanel account login failures and cPanel account access problems.
If you are not the hosting provider, you will want to reach out to your hosting provider directly. The hosting provider is typically the company that you pay for hosting services, and it is also where your domain is pointing to via nameservers or an A record. They will be able to help you with any issues you have with your website, email, cPanel login or your hosting plan.
For more information, see How to Identify Your Hosting Provider.