AEG - major disappointment

In Jan 2010 we have purchased oven AEG Competence D 4101-5 and a hob, and were incredibly happy with the products until they broke. We called AEG for qualified technicians and after 2 visits our hob was fixed (luckily it isn't AEG)<br> The original oven fan (itself) has rusted and was falling apart. However after 3 visits our oven is still not working as expected. Immediately after the replacement we have tested the oven and the baked goods were not baked properly at the bottom. After showing the technician and him testing the oven temperature he concluded the problem is the fan \causing uneven air distribution"<br> Your technician changed the fan but the quality of the baking has deteriorated.<br> After careful inspection with the technician we found that the exchanged (old) fan has 7 blades and the replacement part has only 6"