We asked Peter to clarify where things mentioned in the review took place, in a completely friendly tone. The complete review was a lie - sad to say, and the customer indirectly admitted it after being asked about it several times by saying "I was frustrated".
The customer replied "you are condescending to me" -- offering no evidence of what was written in the review, when we tried to figure out where the things mentioned in the review happened so we could offer our help. We asked again, and again, and again, with similar responses from him. At one point, Peter admitted that he wrote it because he was "frustrated" and to "give him a call to resolve this" (i,e indirectly admitting that the review was not real). We obviously refused as we wanted everything in writing, given that he lied on a public forum about things that never took place in reality. An unrecorded phone call would mean he could accuse us of even more things and we wouldn't even be able to defend ourselves.
Please understand the whole issue started when Peter did not pay his invoice even after it was overdue and multiple reminders being sent, which resulted in his server getting suspended. We did not cause the issue but we were blamed for it, and the whole review (made up of things which never happened) was written because we told Peter that we do not have access to his server as an unmanaged provider and he needs to check his webserver configuration to see why it's denying connections. He got 'frustrated' and decided to bash us with a completely made up review, even though we were only trying to be helpful.
Another unfortunate untrue line here by Peter is that we "threatened to delete all data". We asked Peter to either provide evidence for the things he wrote in his review so we could help him, or admit that he wrote a completely false review (which he had already done indirectly before) or he could move to another provider, since he was clearly so unhappy with us. A full refund would be provided in the last case.
I think everyone would agree that no provider would accept a customer who goes on public forums with completely false reviews. As you may have noticed in his responses here too - he does not really answer any questions and only makes blanket statements such as "they are bad, they are condescending, they are the worst, etc." while offering no evidence.
It is very unfortunate that customers cost small companies like us time and money. I wish him and whichever company he chooses next the best of luck - because people who have a habit of making up things do not really do it once.