Booking.com Refund Issue for Deposit on U.S. Hotel Reservation

I made a reservation through Booking.com for a hotel stay in the U.S. and was charged a $150 deposit at check-in. The hotel informed me that the deposit would be refunded within 3-14 days after check-out. However, I have only received $139.86 and have not been refunded the remaining amount.

Booking.com has been unhelpful, and I have incurred significant phone charges calling their UK call center, amounting to approximately 2,000 ₺. Despite multiple calls, I keep receiving different excuses and requests for documents. Booking.com and the hotel have not resolved this issue. My reservation number is 4806956***.

Please address this matter urgently and ensure the remaining deposit is refunded.