iPhone 6S Plus Poor Call Quality/Microphone Issue

Okay, so the Apple Rep did an Audio Test on the phone at the Apple Store and said the phone is fine. He then proceeded to tell me that the phone is made by imperfect human beings, thus it is not perfect. He also told me that this is true for when you buy a car, etc. I looked at him like he was crazy and explained to him that I don't expect perfection, I simply expect my phone to be able to place calls without interference. I mean, at the very least a phone must be able to make phone calls where both parties can communicate without interference. The rep told me that because there is nothing wrong with the phone he cannot exchange it for a new one. I asked, "What am I supposed to do?" He said, well you can try using wifi calling. I said, well I don't have wifi at work or everywhere I go so thats not feasible. The rep also told me that my Galaxy S3 used more analog signals and that this new iPhone uses more digital signals thus the experience can vary. I was like, "You're kidding, right"? All in all, I left the store not only VERY dissatisfied with the phone, but also VERY dissatisfied with Apple customer service. And this is after I come back to Apple from using Android for over three years. The reason why I wanted to come back was because of Apple's exceptional build quality and support. Talk about a let down. I am so disappointed! I just picked up a new 13 Macbook Pro for $2,000 and now I am VERY worried. I think my options at this point is to crack the screen on the phone and exchange it under the Apple Care or call Kurtis (CBS) in hopes for a solution.

Here is a video I made regarding my experience:

https://www.youtube.com/watch?v=RPq26eApfAI

UPDATE:

I got a call yesterday from Ray (Apple Store Manager). He apologized for the quality of service I received the day before and offered to have my iPhone replaced under warranty in order to eliminate the possibility of it being a hardware issue. I was very happy he called and worked to resolve this issue. I picked up my phone today and was told not to restore from my backup. I came home, placed a call to my wife and the phone worked flawlessly. Then, I updated to iOS 9.1 and tried placing a call again to several people including my wife. The problem reappeared and my call quality was once again bad. I wish I backed up the phone before upgrading to 9.1 because now I can't go back to do more testing. At the suggestion of the Apple Store representative I spoke with while picking up my replacement phone, I contacted T-Mobile and explained the issue. The T-Mobile representative discovered that my SIM card is 14 months old and that I did not receive a new SIM with the purchase of this iPhone (at T-Moblie Store). She offered to ship me a new SIM card free of charge. I now have my fingers crossed; hoping that its the SIM card. I will keep you guys updated with this problem.

I also wanted to thank Ray, the Apple store manager, who worked promptly to help me resolve this issue and the technician I dealt with today at the Apple Store. This is truly the Apple support I expected from the get go. Thank You.