[Q] Huawei P6-U06 Update B508 topic

I've managed to get mysellf in a very sticky situation, I updated my huawei from the international version Jelly Bean to the B508, I then noticed I couldnt connect to the internet via my sim card but everything works okay so seeing the issue I wanted to go back to the stock international version but the phone suddenly fails to read the sd for the update, I tried the local update and the usb drive options all fails, I really need your help guys, either to get me to the stock international rom (downgrade) or to fix this same B508 rom to work with my sim card internet access.. thanks in advance