Delhivery — Delhivery is taking too long to deliver my return parcel back to the seller

Hi!
My tracking number is #[protected]
It's been 10 days since the delivery guy picked this parcel from my house and departed it on the same day that is 3 March, 2022. Today it's march 12 and still the parcel is not delivered. I don't what's happening, they have been pushing the delivery date day by day. I have tracking this and now there's no hope. They don't have a customer care number. I tried to send an email to them but they have stopped using that mail ( they don't respond to customer on email now which is strange) I don't know what to do. Please help.