Its been almost a year and i havent recieved my amended return. I faxed all papers recieved a letter saying they did and still nothing

I filed my amended return and 7 months has gone by and i havent received anything. I faxed in everything they needed they mailed me a letter every month saying they havent looked at my documents etc.  But now i haven't recieved any more letters even when looking on the wheres my amended return website nothing comes up it says their is no case with my info