Okay after trying to contact the phone support two days in a row IN the openening schedule and the nice computer voice telling me i´d call outside of the openening times, i finally managed to get someone there on the phone.
In the end they weren´t able to help me and suggested to try it another PS3 to help to locate the problem.
Okay, so it took a while but i managed to copy my savefiles and get a friend who owns a PS3 as well.
I copied my savegame to be able to have access to the areas and spells i needed to use, because i wasn´t up to play 15 hours or something of gameplay to reach that point i would have a compareable set of skills to test it out.
However, same problems on my friends console - so i will try to call the support once again and see what they say.
I thought i´d just update the status for anyone who may stumble upon this problem as well and since there seems noone official able to help at the moment i hope i figure out the problem and hopefully fix it and post it here then.
Otherwise i think i will try to contact Amazon and see what they say about a refund.