Is there anyone at your student house to send you books if you paid for it?
Pretty sure some of the older delivery companies like DHL offer a service where they bring the box to your house, someone at the house puts the things in the box, then DHL take it and deliver it to wherever needed.
It’s means someone has to be in, but you don’t have to ask your flatmates to go to the post office or anything?
Also, does your uni do online versions of the books? Not as good but another option