Booking.com Shorted My Refund for Vienna Stay Apartments—I Want Full Reimbursement

I booked a stay at Vienna Stay Apartments Tabor 10203 with confirmation number 4810525775, but my reservation was canceled the next day. I was supposed to receive a full refund of $571.13, yet only $556.16 was returned to my account. There was no mention of any deductions, and I was assured there would be no penalty. So why is $14.97 missing from my refund? This is unacceptable! I demand that the remaining amount be immediately refunded to my credit card. Booking.com should not be withholding money without explanation. I expect a prompt resolution, or I will escalate this further. Booking.com, return my money now!