My keyboard is messed up

I bought my laptop 7 months ago, it's samsung laptop with windows 8.1
it was fine when i bought it, then about three months ago the keyboard started writing the wrong letters. I tryed everything and nothing worked, and after a while it worked fine again but now it became worst then before.
r & e work at the same time, if i press one of them the other is written also.
and space & g
Enter & m and many other more

I hope that someone can help