No courier company will touch it because it does not have a street address. Without a street address it is basically undeliverable. The same postal code usually encompasses a group of neighboring addresses. Unless a courier company has a drop off agreement with the post office for packages which most do not, the company has no way to get your package into the postal system without paying to do so.
Contact the recipient, and get a street address you can ship the pkg to. A postal code is a routing mechanism that allows USPS automation to get your mail to the correct delivery route/person and it is up to that person to determine the correct physical address for the last step in delivery.