"Stupid" is a bit strong, @Patricia2147, but you may have just cancelled a booking yourself (versus the guest cancelling). The email is a bit misleading, so I fear you may have been caught out. The 'deduction' sounds like the $50 'fine' for cancelling. If this is the case, you'll also lose your Superhost status.
You'll need to check in with customer service and have them fix this for you. Good luck.