Spanish customs is a pain

I've gotten several packages sent to me from home and not once did I receive the dreaded customs letter that my package was stuck in Madrid.  Until yesterday that is.  I first heard about this awful procedure on facebook in the group that I'm in for the program.  People were telling horror stories about their packages being detained in customs and this long process they had to go through to get their package.  One girl wrote that someone she knew ended up paying 260 euros for her package while another said one of hers ended up in Spain and another ended up back in the U.S. after months of waiting.  The paper you receive barely explains anything and I asked my roommate if she could help explain what I need to do to get it.  She said she had to go to the post office today so when she was there she asked about it.  They told her that more packages are being detained in customs, especially ones from the U.S., and if it does get sent back home you still have to pay a customs fee.  She made it sound like they pick packages at random to detain. 'Sometimes they keep them and sometimes they don't' was her wording.  Well dang.  It's definitely a way just to get more money out of you and it's extremely frustrating.  You only have a certain amount of days to fax these 'documents' and they don't specify what exactly these are.  I have no idea where to even find a fax machine over here and I'm not sure if I have to scan the paper they sent with it so then I would have to find a fax machine and a scanner.  Like that's going to be easy.  Even if I don't get the package at least it'll be sent back home, although it's all super frustrating.