i did a project with one of my clients for 400$

[abdbd20e]

Hello everyone plz pay attention,,,i did a project with one of my clients for 400$,,i gave him 100k subscribers for 400$ but after he got the subscribers he canceled the deal,and wanted a full refund from me. ,,, I have spoken to dispu but I don't feel much benefit ,,, how can I get my money back I want expert advice