Bad service

Ordered and paid for books for my son on the 10th January. I even paid extra for their "express" delivery. Still waiting for those books. Followed up today only to be told that payment doesn't reflect on their side! How is that even possible as they provided me with a receipt after processing payment via card. Call center consultant didn't eveb know how online purchases work and insisted thag I send them a receipt from my bank! I even sent them a full bank statement to show the transaction. Still waiting for their royal response and service!!!