"Correct me if im wrong..."
Ok, you are wrong.
Either you got an incomplete answer or you heard what you wanted to.
A COD requires a driver to do far more than for a nonCOD as you have to know.
Such things as having to interface with the customer, multiple trips, RTS'ing a package, both in the DIAD and then again by the clerks to add labelling to get the package back to you simply because it was a COD.
And if the customer actually accepts and pays for the COD package we incur most of those same labor, fuel (multiple attempts),etc costs and then have the costs of getting the funds back to you.
All of these costs, successful completions of collecting CODs, failed collection of CODs, outright refusals of CODs is averaged out and UPS decides how much they have to charge for this service to make a profit.
I can tell you every driver and clerk out there would be estatic if UPS would quit offering the COD service as it adds contention at the delivery point often (blame the messenger) and is a security, economical and safety risk to the employees involved.
So just send the package without a COD charge, trust your customer and save the COD fee.
Or is there some reason not to trust your customer?
It appears if you are getting COD refusal returns you may have a valid reason not to trust your customer and the COD fee saved you from the product loss.