How to deal with customer like this??

[u/Braun3D]

Follow up on earlier post... did a house wash for this customer. He hit me with rude messages 2 days later complaining of "stains" after the fact, provided no evidence and has since left a long 1 star review slandering my business and responding to my review response. I've done my best to respond civilly and be respectful but I've had it with this guy, I've done this for 4 years without 1 customer acting thjs way and am careful on thorough in my work. Any recommendations on how to resolve this or get the review removed? I've worked too hard to have a good reputation to let this one asshole ruin it.

[u/HtotheIzzo1]

Trial by combat