I accepted this quest and finished it and when i was back at regia to turn it in the quest is acting like it hasnt been selected and when i tried to turn it in it is acting like i havent accepted it also tried refreshing after a few tries and it says i have accepted a quest this one so i cant refresh it, but it wont let me turn it in please help  

Turn on your Mini-Quest journal UI on the screen and use Automatic Walking to take you to the correct turn in point.

Not all bounty quests turn into Regia Deorum. Filthy Grub is one of the ones that don't turn into Regia.

This bounty quest turns into Arthlan.

If you need to know how to use Automatic Walking see the guide here.