If the buyer took too long and made the gig go late , customer support should see that you gave her plenty of time and still had much time left on the order at the time of asking her for clarification or more information.
However , in my experience , that alone is not grounds for them to remove a rating from a buyer. You may ask the buyer very nicely and explain to them that your rating here is your life blood and it’s of the utmost important … Maybe offering a discount on that order or future orders would still net you some income and a chance to get her to change her mind.
Regardless , it’s difficult for buyers to even figure out how to change their order rating that they gave … I had one guy thrilled about my video I sent to him but he accidentally left a 4.5 rating instead of 5 stars… He just didnt realize it at the time … nor did he realize it brought my perfect gig from 100% to 99% … it was the only rating less than 5.0 … and for weeks and several messages … he couldnt find the button to remove or edit his rating.
In the end -
TLDR: Don’t waste your time on it. Contact support + the customer at the same time and ask them to remove/change it … offering the customer some value and explaining the importantce of the fiverr rating. Ask them to explore other reviews to show them you are not a scammer or perform badly on the regular.
Good luck … some people have a heart . Some dont.