Delhivery — Consignment not yet delivered even after 18 days

On 24.9.21, I had booked a courier through Shiprocket., to Kolkata 700039. I had to choose Delhivery courier for availing the service, as there was no other option shown in website of Shiprocket.
My AWB number is [protected] dt 24.9.21.
On 1.10.21 this consignment reached Dhankuni-hub of DELHIVERY (outskirts of Kolkata).
After that, till 8.10.21, it was still lying there. I had been complaining to customer care number of Shiprocket since 3.10.21. and I was given assurance that within 24-48 hours my package will be delivered to Kolkata 700039.
I was not satisfied by Shiprocket's reply, so I checked website of DELHIVERY to find out their customer care number or contact details of their Dhankuni's hub number. To my horror, there is no number of any customer care provided in website of DELHIVERY.
Only address is there and an email id.

I immediately emailed my complaint, but next day I received a copy paste sorry reply from Delhivery.
That's all. There is no resolution of my pending complaint, from Shiprocket and Delivery.

On 9.10.21 evening, I checked the tracking, and again to my horror, I saw that Delhivery has made arrangements for return to origin (RTO) by giving reason- as advised by sender.

Fact is that I have not given any advise for return, first of all. Secondly, where will I give advise- they don't have any contact number??

They are taking us for a ride, and because of this now I am very tensed and feeling mentally disturbed and disheartened, because of their misdeeds, I have to listen to my customer's complaint and I am loosing my good customer.
Since 4.10.21, I am regularly calling Shiprocket customer care and asking them to provide me details of address and contact numbers of delivery address of Delhivery at Dhankuni and Dhapa, so that my customer can call and pick up the said parcel. - but they are not providing me and giving reason that they don't have their contact details. They are not providing even customer care number of Delhivery main office.

I have called multiple times to Shiprocket's customer care, esclated my case multiple times- same reply they are giving-"we are sorry for the delay, we will give resolution in 24-48 hours". I even contacted local booking office of Delhivery at Kottyam- they are also denying to provide me the telephone number and address of their hub at kolkata-Dhankuni.

As a customer, I should be able to get the address and contact number of delivery office, which I am being denied by both the aggregrator Shiprocket and their courier partner Delhivery.

No proper reason is provided in website of Shiprocket and Delhivery- just written as "delayed due to operational reasons"- againg this is their copy paste reply.