Can you still dispute a Local Services Ads lead?
Not in the old sense. Google says "Charged leads get reassessed by our models over time, and may be issued credits automatically." What you can still do is rate a lead in the Lead Feedback Survey, and Google says it "may also occasionally credit leads you report as poor quality" that way.
Two reasons owners used to dispute no longer qualify. Google says it "no longer supports credits for "job type not serviced" and "geo not serviced" leads." Lead credits also aren't available for health care, tax specialists or advertisers in Europe, the Middle East and Africa. For wrong-job and wrong-area leads, your settings are the fix: the job types and service areas you select decide what Google sends.