I agree. The upper is a hodgepodge of parts from different rifles. Plus, it appears that you have a PTS forend. Hopefully they didn't charge you Magpul prices for that.
My advice would be to part out that upper and sell the components, then buy a new complete upper with a flattop receiver.
My advice would be to part out that upper and sell the components, then buy a new complete upper with a flattop receiver.