Booking.com ducking and diving

Had a problem where i was double charged by a B&B booked. Through bookimg. Coms app, they then asked for a proof of payment which i sent, a xay later they asked me to resend it of which i did, when they received it a clumsy excuse was made i then downloaded a bank provided proof of payment of which when they received it they then said i should handle the. Matter with the B&B directly.... Pathetic booking site and customer service