no answer from guest

Reservation was made on 12th June for 20th July.

I did as follows: 

- 4 messages via pulse app

- 2 direct e-mail provided by booking.com

- SMS via mobile number

- message to customer service (reply - we contacted the guest and asked to contact you)

- request to cancel reservation two days ago.

All of this is without result. Any advice for future would be very much appreciated. No- show is the only option but what about losing income.

Thank you.