Apple is not here on this forum. We are just other regular users who are volunteering our own personal time to assist people. If you want to speak with Apple directly, then you will need to use one of the other options under Support.
Auto-correct is tricky on macOS. There is a system wide setting in the Keyboard System Settings. You need to scroll down to the "Text Input" section and select the "Edit" button for the "Input Source" you are using (I only have one item here on my systems). You will see multiple auto-correct settings listed which you can disable.
Some apps may have their own auto-correct settings as well so you will need to check the particular app's settings to adjust those as well. I know for TextEdit, that I have to close the window & create a new window (or quit & relaunch the app) before TextEdit will utilize the updated settings. Other apps may or may not need to do this. I don't think I had to log out & back in for the Keyboard System Settings modifications to take affect, but you may want to do so if you are still having issues. Even a system reboot may be needed in case you have something else going on with your system where it just needs a bit of a cleanse.