Brand new phone giving problems

I bought a brand new Samsung Galaxy S6 Edge on contract, and I am experiencing a lot of difficulty with the phone. Various technicians have told me there is nothing wrong with the phone, but this cannot be because my previous S4 mini has a much better preformance. I want this phone to be traded ASAP for an iPhone because this is absolutely unacceptable. I do not want a replacement, I want a different phone because many other people have experienced similar issues as I have.