I have got the TNT sports pack with bt, I have just activated discovery plus for bt so is discovery plus free for my TNT sports and my bt

If you've activated Discovery+ through your BT account as part of your TNT Sports pack, then yes, Discovery+ should be available to you at no additional cost. Typically, BT offers Discovery+ as part of certain bundles, so make sure to check the terms of your subscription on the BT or TNT Sports website to confirm that it is included. If you have any questions or issues, contacting BT customer support directly would be the best way to get accurate and specific information regarding your subscription.