Problems over and over!

Long story short I got my samsung S8 on contract last year and got a samsung J5 prime included in the upgrade.

The J5 was working perfectly for the first few months, then started having multiple issues. 1 of 5 times the phone went in we noticed that the phone was doing its own thing (typing by its self and opening random apps) i took the phone in for repairs as its still under warrenty. The phone came back and they told me they found a bug on the phone and did a software update. 2 out a 5 times the phone went in l, the phone was still doing its own thing and yhey then replaced the screen and motherboard. Wich should make the phone brand new. 3 out of 5 times the phone went in because the screen would flicker and brightness would dim at times out of nowhere and had a memory issue and they did a software update. 4 out of 5 times the phone went back in because the problem kept happening and still had the same issues, the phone went to samsung headoffice as a escalated problem. They did a software update ! 5 out of 5 times i told them that the issue has not been sorted at all, they keep doing software updates and we want yhe problem escalated and want the phone replaced and told them not to do a software update! What did they do? Software update! A software update isnt going to work if they have done it 3 times before and it sorted out nothing! Im highly dissapointed in the service and help from Vodacom. Me and my family have been with vodacom for 12 years + and my mom and dad since they had theor first ever phones and contracts. PROBLEM NEEDS TO BE ESCALATED AND FIXED!

Seems like all you know how to do is software updates!