Daily Burn is a company separate from DietBet, but many of our players like to use both services, so they run offers at the time of game signup. Unfortunately, we don't have access to your Daily Burn account info, but we can point you in the right direction!
Here is the webpage for their support team: https://dailyburn.com/support
When you opted into Daily Burn you would have also gotten an email from them with information about your membership.