PCC won't work as it will detect modified software - Your only option is to find a .ftf firmware file and manually flash your phone - Beaware that in doing so will result any and all info been lost as it will factory reset your device
The only M Dual fimware I can find is here which is Central Europe and a good guide is here - Ignore the titile as it's the process you need to follow and simply substitute the downloaded firmware above at point 2.
