Keys stick and cursor moves on its own.

I have an ideapad 320 just a few months old: I hate that lenovo cursor jumps around and it gets worse with use. Sadly this is the same problem I had with the last lenovo, exactly the same! Why oh why did I buy another lenovo??? The salesman assured me this was a better model and it was for about a week. Hate it. What to do with it now?