Reporting Messages not working

I think you misunderstand. We’re not asking for any information about the action, just that the action was taken. I used to get messages which stated “Thanks for helping make Xbox Live safer for everyone! We took action on one or more of the recent complaints you filed.” Haven’t gotten one of those messages in months. Action is not being taken. I know action is not being taken because when I report a message for profanity, the person who sent it continues to send messages cursing me out. So clearly nothing is being done.

I agree with you. I've had people threatening my life, saying vile things about my mother, threatening my IP address, telling me to [mod removed], telling me they were going to kill me, and that doesn't even account for all the vile language I received.

Again, that clearly is not true since they’re still able to send messages. Nothing has been done.

Since you reported them action will be taken. You should also block them.

The enforcement team doesn't always send a thank you message when they take action on someone. Just because you haven't received one, doesn't mean nothing is being done.