No bootable device after failed window installation via bootcamp

while trying to install windows 7 via bootcamp on my mbp retina today i really messed up.

after getting into the drive selection in the windows installation utility i deleted the other partitions(3 of them - as i remember one 60mb one 200mb) to get more space for my bootcamp partition. after i deleted them(not formatted anything - just deleted) - it just showed one huge unpartitioned disk with the whole ~250gb of my ssd. i realized that i messed up and exited the installation routine just to find out that i can't boot into anything right now.

when i do a regular restart it shows an error message "no bootable device - insert boot disk and press any key" - i also tried the "alt+cmd+r" method which doesn't do anything...

please send my any ideas/tipps how to go on - i got really important documents on that machine and i haven't made any backup.