I Can't Pay for My Booking.com Vacation

I booked a vacation through Booking.com for the month of July. I chose the 'Pay Now' option, but I keep getting messages saying that I don't have enough money or that the transaction was declined. I still have some time before my vacation. Can I go to the hotel and have a great time on my vacation? Hey, can anyone lend a hand? Hey officials, can you please get in touch with me? I've been trying to reach out but haven't been able to get a hold of you. There's no menu for customer service that's easy to find.