Default I cannot go back to stock after flashing beta 4.4

Guys,i got myself in abit of a trouble as it seems...I got the F320S variant crossflashed to F320K with the latest beta kit kat.

The phone works fine,but now i cannot go back to stock anymore in order get the OTA,it returns a error everytime i try to flash it,officialy or not.
There is no root or recovery to be able to change anything so im kinda stuck...Any suggestions from people with more knowledge would be really helpful.

I can flash only K firmwares now...without giving me errors.Tried to flash a 4.2.2 K firmware tho,but it was stuck at boot,after flahsing it.

If any dev has the non beta kdz file of the korean upgrate msg me please...