Quick learning:
Be the squeaky wheel to get your bike fixed.

Here's What I did that Worked to get my repair done in under a week:
I first made an appointment using the 'Beeline' mobile repair service. I used the link they sent to my email to book the next available opening. I then contacted Radpower via the website chat and notified them that I had a scheduled repair appointment (Tuesday, 1/31, 9am) and that I hadn't received the replacement tires yet. They seemed to immediately send the tires upon request and they were delivered today. It feels good to know this will be over on Tuesday...