My moto G 3rd generation screen just shattered and I was wondering if I can get it replaced or do I have to buy a new phone?
Republic does not have a screen repair
a shattered screen is typically not covered under warranty though you may want to check with the credit card you used to buy the phone
Motorola may do a phone repair though their support https://motorola-global-portal.custhelp.com/app/product_page/faqs/p/30,6720,9390/#/how_do_i
Though they charge a lot for it and they typically just send out a refurbish phone than repair the one sent in
there also third party phone repair places (local shops)
here a national chain CPR Cell Phone Repair | iPhone, iPad & Computer Repair Services