Why people do this? I am so sad

Hello everyone, is there any way to defend myself against false accusations? Someone I don't even know is spreading lies that I ripped someone off. I did NM or venom service for several people, and out of nowhere, someone commented on one of my posts that I'm a scammer and then wrote it on my main profile, where I have a lot of positive reviews. Honestly, I have RBH dilos, scorpion, GHH, and others, so why would I rip someone off for kitsune when I can buy 10 of them? I'm really sad. I'm trying to help the community here, and some jealous people are doing this.