Problematic Samsung S5 Mini

My Father did an upgrade in January 2015, he did take Samsung S5 Mini. In July August this phone start giving him problems. He did go back to Vodacom in East London. They did check it , software upgrade no improvement. Then Samsung call him about this phone, they ask him to do sim swop, they said it wont give him problems. Problems starts again, today 19/11/2015 he did go to vodacare at Vincent Park East London. The person who was dealing with him said he must call Samsung because its their product, my father didn't take contract with Samsung , he did sign contract with vodacom. This is so unprofessional, he has taken this phone more than five times. He travels from Butterwoth to East London which is more than 100 km and no good service. Is this how you do to your customers that you call them loyal customers? Someone must sort this out , because my father is stressed people cant get hold of him. Someone who knows how to treat a customer must solve this problem very soon. This is a very unfair treatment , you cant take phone for repairs more than five times and phone is not even a year old. Now he must call Samsung how , for what ?