Air Asia — Wrongly charged for boarding pass to my customer after promising it wont be charged

I am a travel agent who booked a ticket for my client. As after booking ticket I tried to generate boarding pass which due to the problem in the website I was unable to do so. Lastly I called to their groupdesk team and they also tried many times but was unable to fill boarding pass page so they told they will pass a note not to charge for boaarding pass yet they charged.
I have given the full full voice recordind to the helpdesk about what they have told but still they are not refunding the amount.
Passenger name- AMAR ROY
PNR-Y81SGN