Worsened my Samung Note

I had a problem with my Galaxy note, it kept on flickering non-stop, it could switch itself off while I'm still using it and would just go blank. I decided to take it to Samsung in Tyger Valley (Western Cape) hoping it will be perfect when it comes back, I receive an SMS 3 days after having dropped it off. I signed for it, now I get home and I want to use it, it's in a worse condition than it was. I'm really upset! Never ever will I buy anything from Samsung again!!! This is bad enough to be repeated again!!!!