How to get refund for returned product

I returned/refused delivery on a modem on February 5, 2025 and confirmed receipt of product by Arris on February 19, 2025. I was told to expect a refund within 2 weeks of 2/19/25. I called on 3/5/25 to check on refund status and was told it was expedited and I should receive email confirmation. No message received. I called on 3/6/25 and was again assured it was expedited and I should receive a phone call. Still waiting for a phone call. In spite of confirming my email address multiple times, I have never received an email, not even confirmation of my original purchase on 1/31/25.