Wow, I am sorry you are going through this.
It is understandable that they need more time but it is unfair to you to be waiting half a month or longer to get paid for the work you've already done for them.
Honestly, if it is affecting my Fiverr status, I would personally let the buyer know that I'm going to resubmit the original video and get paid for my work and still honor the revision request whenever they are finally ready. THAT would be fair and amicable.