It's their culture of saving face. The solution is extremely simple.
You tell the person "I was told I had to pay this <X fee> to release my package but I don't know who or where I pay" while waving the cash around cluelessly. The person will 100% then offer to take it and "handle it from there" under the stupid guise of plausibility.
You tell the person "I was told I had to pay this <X fee> to release my package but I don't know who or where I pay" while waving the cash around cluelessly. The person will 100% then offer to take it and "handle it from there" under the stupid guise of plausibility.