Brand New Phone Faulty

I bought a Hisense phone from Foschini and two weeks after it became faulty. Screen jumping up and down on its own. Dails up my contacts on its own, and no button works, freezing all the time. I have never been so disappointed and fustrated and worse I am loosing a lot of business as my phone is my business hub. I don't buy Hisense, I am a Samsung girl but the sales person was so convincing that the phone is better than Samsung and I regret buying this phone. Foschini wants to take it in for repairs that will take up to 6weeks, why would a new phone that is less than a month need to be repaired? I hate Hisense and so disappointed and regret buying this phone. Hisense needs to go back to the drawing board in this one because you will loose a lot of clients. What do I do now? How do I conduct my business with no phone? This has been the most inconvenient situation ever.