No. Microsoft will not charge you for Defender anti-virus software.
I got an email that claimed to be from Microsoft and that they had charged my account $299 for a one-year subscription. If I did not want this renewal, I was to click a link, supply information and they would refund my money.
The first question I usually pose at people about things like this is: Do you use the program or product? In this case if you have a Windows PC then Defender automatically is there so this question not a help.
Second thing to look at it is the FROM address. In this case it came from something weird, which told me this is a phishing email.
Third item is, hover over the link and see in this case if it goes to Microsoft. It did not, but instead to some strange address. Again, a red flag for phishing email. However, this one only works if on PC or laptop. On phone you cannot hover over a link to see what real link is. A limitation on phones.
The last thing to remember in this case is the program they claim you were charged to renew is a free program. Microsoft includes it free with Windows and I have never seen any rumors they will start charging.
Defender will work with another anti-virus program. I have never seen Defender block or catch viruses, but maybe it does it in background. I use Avast with it to be more complete.
When you receive a strange unexpected email, Stop, Think, then Act. In this case it was phishing. People send ones claiming similar on Prime, but even if time to renew, be safe and go to Amazon to renew.