Billed 3x for one consultation - who is pocketing the the other 2 consultation fees?

i just received an SMS from your accounts division indicating that there was an outstanding account. Intercare submitted three accounts, one for for 28 and two 29 January 2019. Payment was made on the account for 28 and 29 and the second account for 29th Jan was rejected. Intercare has now received payment for accounts dated 28 and 29 and holding me liable for third account which was rejected - i only visited the your rooms on 29th Jan - HOW IS THIS RIGHT? WHY ARE YOU CHARGING ME 3 CONSULTATIONS WHEN I ONLY SAW THE DR ONCE?