You can only dispute work for the last week's hours. When you hire someone on an hourly basis, you pay for the time spent working, not any specific deliverable.
@Jake M wrote:
I have a freelancer that I've been working with the past 8 months. We're at a point where no physical product has been supplied but there has been work done on the project, 100+ hours.
Why would you let something drag on for 8 months without seeing any result?
I'm very sorry that you have had a bad experience Upwork.
But absolutely none of what you are describing you think Upwork might do to resolve this is any way based on anything that Upwork claims to do.
100 hours is a LOT of hours to pay for without receiving anything.
I strongly advise you to work with a qualified project manager.
A project manager to whom your freelancer(s) report to would have been able to tell you after only an hour or two if this particular freelancer is legitimate or a scammer.