Delhivery — I'm complaining about a parcel which is not delivered to me but status is showing already delivered

I have purchased 3 appreal product from a Facebook seller on 9 th May, through delivery courier she had dispatched my product, today is 28 th may still I haven't got my parcel, yesterday when I got the tracking I'd from the seller and track my parcel through delivery app it was shown that my parcel is already delivered. Which is not true, I haven't got parcel of tracking I'd[protected] ...
Kindly check on this matter and do the needful.