I use AMD Radeon R9 380x 4096M card and my rig is running at 2.912 GH/s rate for ETH at hiveon pool using phoenixminer. But unpaid balance is not updated. my wallet address is correct with coinbase. what could be the reason.
You have fake hashrate from your card
3 GH/s on ethash from R9 390 it’s unreal hashrate value. Your card didn’t produce any valid shares. So it’s normal that your wallet not updated: no valid shares - no money 
I also thought about that. How can I get it correct. I am a beginner. Your guidance is much valuable for me to learn and get this thing correct on my old GPU. Then I could invest for new Cards. Thank you very much.