Poor Customer Service and utter incompetence from top to bottom

I bought a CM1000 cable modem from Best Buy in December 2017. In May 2018, the modem stopped functioning. I called customer support on May 19, and was issued an RMA number over the phone and via email with shipping instructions. The defective modem item was shipped on 5/23/2018 and received by Netgear staff 5/25/2018 (Memphis TN) based on the Proof of Delivery from UPS.  In the meantime (May 19, 2018), I purchased a replacement modem (same model) from Best Buy.  On May 29, 2018, I received an email from Fedex with tracking number and a delivery date of May 31. I have not to this day received the modem. I have called Netgear support the past two days trying to get information regarding the RMA. I was told that the RMA does not exist and that my profile does not have anything associated with it. Later in the conversation I was informed that the RMA I provided (and that Netgear provide to me) was assinged to another customer and the paperwork was poorly filled out by Netgear staff.

By the way, the second Netgear modem I purchased (May 19) crapped out on June 4, 2018. I was able to return it to Best Buy and have since bought an Arris SB8200 modem.

What I would like to know from Netgear is, where is my under warranty replacement modem? Why is your company so incompotent? Why do you call your staff "expert" when they are clearly amateurs? Maybe you shouldn't be outsourcing workers. You should be outsourcing your entire management structure.