Xbox controller analogue sticks keep going bad

That sounds extremely unusual. My original Xbox One controller of fours years is still working and my new one is going on for 2 years. Are you sure you are not too rough on them? Light touches are all you need.

Anyhow, you can register it for repairs here: https://support.microsoft.com/en-us/help/18878/microsoft-xbox-device-registration-process

Best,

Nozzle

Here is the info on getting the Controller serviced.
https://support.xbox.com/en-US/xbox-one/accessories/wireless-controller-broken-wont-work You will put in a service request here:
https://support.microsoft.com/en-us/devices
under your console.
Change the category to Accessories and then under select issue type select Controller. Then input your PID number from the controller and click create repair order.

If it is still under warranty then you will need to contact support directly for assistance else you will have to replace it. https://support.xbox.com/contact-us

9th? Could be user error? I play almost every night and have had the console since release day and have only had to replace 1 controller. In saying that, my second controller is starting to drift so I will replace it soon.

I think stick drift is becoming increasingly common because of the number of titles that rely on you clicking the sticks for certain activities, especially whilst still moving the sticks around. It was a lot worse with the Xbox 360 controllers, but I've
gone through maybe 3 Xbox One controllers this generation, including two Day One controllers.