Im finding any iso over 800 is poor quality photos, anyone else finding this,
I don't have the D500--mine include the D7200, D7100, D750, and D610--but I can't believe the D500 would be any worse than the D7100. I used that body for hundreds of drama photos that were printed. My ISO was at least 2000 and sometimes as high as 3200. It wasn't a problem.
As Fred mentioned, there are a number of plug-ins and/or alternative programs that address noise. Nik Dfine is one that works very well. I invoke it within Photoshop. After it runs through the Auto setting, I go in and lower the amount of noise reduction so things don't look so plasticy.
What are you doing during post processing? The more you crop, noise splotches become larger (not as fine-grained). The more you raise shadows, the more noise you introduce. Nailing exposure or erring on the side of slight over exposure helps since that drastically cuts down on having to raise shadows during post processing.
If you are using Camera RAW (or Lightroom), in addition to the Luminance setting under Noise Reduction, you should play around with the Color Noise slider. That directly reduces the colored splotches. Just don't overdo Noise Reduction. As I said earlier. too much noise reduction makes things look plasticy.
I routinely shoot at ISO 3200 to 5000 (and sometimes higher) during Worship. Those images get printed for a calendar that has pages slightly larger than 8.5x11. It hasn't been an issue for me.
If you shoot a lot of jpeg, then consider turning on Active-D lighting if it's an option on that body. Active-D lighting lowers contrast so more detail is visible in the shadows. That means not having to raise shadows as much during post processing. Using non-destructive editing such as adjustment layers (such as a curves adjustment layer in Photoshop vs. Lightroom or Camera RAW editing to the image) is better than applying adjustments to layers directly. When adjustments are made to the file directly, it changes the pixels. I'm wondering if what you are doing during post processing is causing more noise to be visible. If you have a NEF you can upload to Dropbox (or some other file sharing site), let some of us look at it and have a go with editing it.