My friend buy oppo F1s in 1st week of November and he also not used phone for hardly 2 days and display started to Flickr whenever call came.Screen display always binks whenever phone rings.Even service center of oppo is worst than their phones. Camera is good but overall performance rate of phone is bad. Having ram of 3gb is not useful as phone lags when we play games. Fingerprint sensor of phone is not so quick.So oppo F1s is only good at camera but other things are worst.