This statement from the OP.
....... "change visa type must be done while there are 15 days left on existing tourist visa, ie dont go to immigration with 5 days left on your tourist visa expecting to change to type O. Wrong! they wont allow it"
Suggests the OP went without 15+ days remaining on permission of stay.
An oversight on his behalf that requirement is nothing new.
That was for non O.
You are applying for 12 month extension. That's different.