ln permission denied

Question

So I've set up transmission (the torrent app) to run a script on my torrent to automagically move my torrents and create symlinks to them. This is the script:

#!/bin/bash

curl -d "email=email.address@gmail.com" \
-d "&notification[from_screen_name]=$TR_TORRENT_NAME" \
-d "&notification[message]=Torrent has finished downloading." \
http://boxcar.io/devices/providers/key/notifications;

tid=$TR_TORRENT_ID
name=$TR_TORRENT_NAME
hash=$TR_TORRENT_HASH

echo -e "checked $tid - $name - $hash \n" >> /home/wouter/Apps/transmission/logfile

antwoord=$(php /home/wouter/Apps/transmission/determineaction.php $tid $hash 2> /dev/null);

echo $antwoord >> /home/wouter/Apps/transmission/logfile

actie=${antwoord:0:1}
torrentid=${antwoord:1}

echo -e "actie $actie - btnid $torrentid \n" >> /home/wouter/Apps/transmission/logfile

if [ $actie != 0 ]; then

    antwoord=$(php /home/wouter/Apps/transmission/returnfolder.php $torrentid 2> /dev/null);
    seizoen=${antwoord:0:2}
    serie=${antwoord:2}
    seizoen=$((10#$seizoen))

    echo -e "serie $serie - seizoen $seizoen \n" >> /home/wouter/Apps/transmission/logfile  

    mkdir -p "/mnt/hdd3/Series/$serie/Season $seizoen"

    if [ $actie = 2 ]; then

        transmission-remote -t$tid --auth=wouter:neirod --move "/mnt/hdd3/Torrents/Broadcasthenet/Downloads"

    fi

    ext=$(echo $name | tail -c 5)
    linknaam=$(php /home/wouter/Apps/transmission/returnname.php $torrentid 2> /dev/null)

    echo -e "extensie $ext - linknaam $linknaam \n" >> /home/wouter/Apps/transmission/logfile

    if [ $ext = ".mkv" ]; then

        ln -s "../../../Torrents/Broadcasthenet/Downloads/$name" "/mnt/hdd3/Series/$serie/Season $seizoen/$linknaam" 2> /home/wouter/Apps/transmission/error

    else

        ln -s "../../../Torrents/Broadcasthenet/Downloads/$name/*.mkv" "/mnt/hdd3/Series/$serie/Season $seizoen/$linknaam"

    fi

fi

As you can see I've built in some logs to check where things go wrong. Everything goes well until the creation of the symbolic link. There the code spawns this error

ln: accessing `/mnt/hdd3/Series/Revenge/Season 2/Revenge - S02E09 - Revelations.mkv': Permission denied

I think transmission executes the script as user 'debian-transmission', so I've tried to execute it with this user. No errors.

I tried giving 777 permissions to the destination folder. This doesn't solve anything.

Why do I get a 'permission denied' and how can I solve it?