You should never “just wait for CS’s response,” especially not when you only have a few minutes left to deliver your order. CS can take up to 24 hours to respond, and you don’t have that time.
You should never let the order go late as you could end up receiving an automated 1-star rating from Fiverr.
I am sorry that you didn’t get better guidance here as you came at the last second to look for help. Had you come earlier, you might have received better responses.
What you should have done is initiate an order cancellation via the resoultuon center (or by creating a CS ticket) before the order reached its deadline. Unfortunately, it is too late now to do anything. If you deliver the order now, you might get a ToS warning for partial/incomplete delivery. The only option (I think) you have right now is to just let it be… Don’t deliver anything. Once the buyer decides to cancel/get a refund, you will receive an automatic 1-star rating from Fiverr. Unfortunately, I don’t think you can even respond to the review to share your side of the story (about how the buyer had asked for something you don’t offer, etc). I think a 1-star rating is the lesser of the 2 evils (you wouldn’t want a ToS warning in your record).
I hope this serves as a learning experince for you and that you are better equipped to deal with such circumstances that might arise in the future.