Retailers who carry Public Mobile - like Walmart and London Drugs - are often able to fix issues related to the phone, software, hardware. They don't have to, and sometimes they won't, but often they'll be happy to do what they can.
Issues related to account (Self-Serve) can only be fixed by Public Mobile. Send a private message to the PM Mods or obtain a support ticket from the SIMon autobot. Expect a delay - maybe a few hours, maybe a day, maybe two or three days - but at least you don't have to spend all that time waiting on hold or waiting in line.
No, there is no customer phone number you can call, but I felt this is better because you can just post your questions in community or contact moderator and get the solution, no need wait on the phone for next available agent for hours.