You can contact Apple directly here:
Contact Apple for support and service - Apple Support
They will not be able to give you your email address as that is information only you would know and frankly that is how data breaches occur when a company is able to divulge personal information. You could have sold your device to someone else and they could be attempting to learn your Apple ID email address or someone may know your phone number and be attempting to get access to your device. They do provide a Support Article that may help you determine what that email address could be:
If you forgot your Apple Account primary email address or phone number - Apple Support
Even with the original purchase receipt from Apple or Authorized Apple Seller, all you would be able to do is erase the device to set it up as new again. You would not be able to recover any of the previous data. The purchase receipt proves you own the device, but does not prove you own the data on the device, which could be from any other users Apple ID/Password.