Did I miss what machine you have? All machines are not the same. I have an APQS and I have to say that I have only had one instance of having tension trouble and I almost
never use the same color thread or brand top and bottom, and I don't adjust tension for each quilt or thread. You should not see pokies. If there is nothing wrong with the machine, you should be able to adjust the top tension to not see black dots on white thread no matter how big the needle! Call the people you bought it from and see what can be done. You still have a warranty for a while yet; get satisfaction or you will never be happy with this machine. Even if it's operator error at least find out.
BTW, on my machine a slight turn does not affect the tension. It requires at least one full revolution to start changing. I think this machine is the only one I've ever heard requires this. I don't mean to imply that this is what you need to do. Although I have heard it said to tighten the tension too tight and adjust it down until tension is good, testing between each adjustment. If I ever had to do this and didn't reach good tension really soon, I would likely give up quilting. I don't have that kind of patience. My name is Jan, not Job.
I hope you get this resolved favorably. There is nothing like seeing good tension using two colors.