Locked Out of My PS4 Network Account

I've been having a hard time getting into my PS4 Network account, and it's been really frustrating. I've tried a bunch of different things to fix the problem, but nothing seems to be doing the trick. The thing is, I've spent a lot of money on fancy games and virtual items, all connected to that account. I can't log in because the authentication code is being sent to my old phone. The fixes I found online haven't been helpful at all. To make things even worse, there's no way to find any contact information to ask for help.