i recently tried to get a parcel delivered from the uk to ginestar in spain, i paid a crowd of jokers called world wide parcel service to deliver to the post office in ginestar as advised by more than one person, i arranged for the parcel to be collected on the Thursday before i flew out on the Monday so i would be here to collect, i got an email on Friday saying the post office had refused delivery i gave an alternative address and offered to collect if they had a depot any where near bye, i did not get a reply until Monday afternoon informing me that the parcel had been returned to the uk but as a good will gesture there would be no charge but i would have to pay to have it sent from somewhere down the south coast to my home, my emails have not been answered for 2 days if you need to send a parcel do not use these jokers

Parcel delivery can be tricky here unless you live in town with a proper street address.  You say that the post office refused delivery.  My post office say they will take delivery but most of the couriers will not deliver to a post office.  Your options are to have it delivered to someone you know with a proper postal address (not a PO box) or use MRW and ask if you can collect from their office (use that as the delivery address).  There's a convenient office in Amposta.

There's an MRW in Tortosa too, just off the Milennium Bridge roundabout and they are excellent.  They deliver out to us in Mas regularly and if we aren't in they leave it at the bakery next door, no problem.  I think if you don't have a proper address you are going to have trouble getting anyone to deliver though.