i checked the level many times since the oil change,, it was ok,,well as you live in Saudi you have plenty of oil so no problem.
on a serious note when you did the oil and filter did you run the engine for a few seconds and then recheck the level ?
my 04 needed an oil seal in the water pump but that was just an ooze and not like oil loss you describing !!
have you looked at your plugs are thet oily ? are the exhaust's grey or oily at the cans outlet?
im more in favor of semi syth oil but that's not the reason your bikes losing oil.
no sign of oil in exhaust tips,, i would notice oil residue in my boots and pants coz i got the those short exhaust tips off ebay,,
this eliminates internal engine issues,, right?