Undeliverable as addressed but address is correct?

[carrythespark]

I recently purchased an item that has since been marked as undeliverable as addressed according to the tracking. I'm unsure as to why this happened as its the same address I have been using for the past year and i've made several orders within the last month as well without issue. I'm assuming the person I bought from left off some detail but after asking I was simply told i'd have to wait until they get it back from usps and then I could decide if I want a refund or it to be sent back again. The problem is I heard this could take a couple of weeks up to even a year to be returned to the sender and I only have a certain amount of time to ask for a refund. I've already visited the post office my item was last at to see if I could pick it up but I was told they did not have it. What are my options?