Unhappy customer

I bought a phone in June, last week I have to send it back due to screen operating itself and it had some line on it, changes the original colour, it's a week. I personal delivered and it's inconveniecing me. I'm told it is LED thing problem can please Vodacom give me a new phone because once it repaired it will be on going to have the same problem, I was at Krugersdorp Keywest.