Client loves work but the person paying thinks it looks cheap and feels the price was too expensive

When the person paying and the person using the project are different
You can end up in a sticky situation
What if the user loves it?
But the buyer does not?
Your job is to deliver the outcome they were looking for
So find out why the buyer thinks you fell short
Is it in the original brief?
If yes then make it good
If no then you've done what was asked