I think you are expecting things to be too easy. No-one here can give you a definitive answer as to what your problem is, just suggestions of possible causes and solutions. You seem to be rejecting each suggestion out of hand because it is not what you want to hear.
You have to do some work yourself. First thing you have to do it to use Google to see if anyone else has this problem. Surprise, surprise, it seem to be fairly common with these cards. Various threads give suggestions of things to try (one I read suggests that the voltage on the card may be too low, for example). But you have to try these things for yourself to see if any of them help in your case.
You are naturally frustrated that, having spent a lot of money, things aren't working as they should. That's a risk that you take when building your own system. And, at the risk of frustrating you further, I would have to say that it is probably more sensible to follow the recommendations of the manufacturers of the various components than those of anonymous strangers on Internet forums. That way, if you do have a problem, the manufacturer can't say "it's your fault, you haven't followed our recommendations". You say "I bought a 1000$ gaming pc", but the truth is you didn't. You bought a bunch of components that you thought were going to work together; it's possible that - somewhere - you were mistaken.
So try a few things like underclocking the CPU, bumping the GPU voltage up a little (but only a little!) and see if they make any difference. It may not be a long-term solution but at least it gives you some idea as to where the problem lies. Troubleshooting computer problems is not guaranteed to be an easy task. If you can't do it, or don't have spare parts to try swapping out, then ultimately it may be easier to take your computer to a repair shop that has these facilities. This is why many people are happier to buy a pre-assembled computer.