Double Booking

Advertised a 7 day holiday for the 2 Jan to 9 Jan 2026. Two people called me to say that they had paid and expected accommodation from 24 and 27 Jan for which I had no booking. Very embarrassing. No contact details available to question what happened. Accepted one offer from but no payment received. I said that I needed to recieve the money before giving out guest certificate but no reply (not sure I they even received as no contact details given out)