Can the agency upgrade a bad hotel room?
If your room is severely substandard, the agency will immediately contact the hotel’s senior management to leverage their B2B relationship and push for a room change or a free upgrade. Agencies have far more negotiating clout than a single traveller complaining right at the front desk.
If the hotel is fully booked and cannot rectify the issue, a premium agency will actively look for a different property nearby, then coordinate a quick transfer to salvage your stay.