Did you fully delete your provisioning profile from PGB and re-upload it? I've checked your build log and the problem is pretty clear -- you've uploaded a certificate with a key starting with 7974***********, while your provisioning profile only contains one certificate starting with 8175************. These numbers need to match.
A common problem is that people delete and re-create their certificate, but forget to recreate and re-upload their provisioning profile.
I didn't delete the provisioning profile from PGB, I just added a new key. I deleted all of my certificates and provisioning profiles from the developer portal and remade them and I still keep getting this issue. Could I be doing something wrong when I'm recreating them? I re-upload the new pair every time.
I didn't delete the provisioning profile from PGB, I just added a new key.
Perhaps you are building with the old profile still? Perhaps ensure you have deleted all of your older keys from Phonegap Build.