Let me make sure we’re on the same page.
When you activated the phone in the Republic app, did you provide the correct e-mail address and successfully move your number to the new phone, or did you provide the wrong e-mail address, resulting in the creation of a new account and assignment of a new number?
When you set up the phone, adding your Google account for the purposes of Gmail, Photos, Calendar, and Contact syncing, did you use a Google account that does not match the one on the old phone?
These are two very different problems with very different solutions, and I don’t want you to lose your phone number thinking these two problems are in any way related.
If the answer to (1) is “yes, I used the wrong e-mail address, created a new Republic account, and now my phone has the wrong number” then you’ll need to cancel that service line in the Account portal and re-activate the phone using the right Republic Wireless account credentials. But if your preferred phone number moved to the new phone, don’t cancel!
If the answer to (2) is “Yes, I entered the wrong Google account and nothing from my old phone is syncing to my new phone” then you can change the Google account on the phone in Settings > Accounts. Just tap the wrong account and tap “remove account” then go back to Settings > Accounts and tap “Add account” to add the correct one.