Returned parcel and never sent collection slip

I have been waiting for a parcel to be delivered since 24 January 2015. When I enquired from the sender, they send me a mail stating the post office sent it back because I never claimed my parcel. I have been going to the post office everyday since the 24th January 2015 to check my mail. They never put a parcel collection slip in my mailbox and just sent my parcel back.