I started using Square about a month ago with one client so far. With my second invoice...

I started using Square about a month ago with one client so far. With my second invoice to him, he tried making a payment and keep getting declined but his card has no problems. I tried to make a $* payment w my debit card and my card was declined too. There is no longer an option to call or message customer support just “email”. I emailed asking why this was happening. First response I got a response saying “my inquiry will be assigned to another square team who can further assist me”. After * days, I did not get a response so I reached out again, i received same type of response in less than an hr. Then nobody has reached out so everyday I would follow up via email and no one replies*Now. I don’t want to create another invoice for my client (director if a movie set) and he gets declined again because it looks so unprofessional. What could be the issue?