A support desk waits for problems. A COD call centre goes looking for them, before they cost anything. Its job is to remove the orders that were never real and to repair the ones that are, while the parcel is still on the shelf.
Everything downstream depends on it. The last mile can only be as good as the address it was given.
MDM Express runs local call-centre teams in each market and confirms at a 75% rate. The remaining 25% are cancelled before dispatch, which means they cost the seller neither a delivery nor a return.
The most common reason an order is cancelled is simply that nobody answers. An order is only given up after three days and more than nine attempts, and the no-answer share is pushed down by calling at different times of day and following up on WhatsApp rather than relying on the call alone.