Complex sentence: Several e-commerce companies hailed the demonetisation decision as an impetus to an increase in digital payments, hoping that it would lead to a decline in COD returns which could cut down their costs.
Split into simpler sentences: Several e-commerce companies hailed the demonetisation decision as an impetus to an increase in digital payments. They believe that it would lead to a decline in COD returns which is expected to cut down their costs.