Single Status Update
I understand you are having issues trying to remove old messages from your inbox. I will try and explain how you can delete them.
The first thing you need to do is go into your Inbox.
Once there, you will see a list of all of the messages that you have received from other members. On the left side of each message in that list, just below the picture of the sender is a little box you can click on. When you click in this box a little checkmark will appear in the box. This is how you select the messages you want to delete.
When you click on the checkbox, two new buttons will show up at the bottom of your screen. One of these boxes will have the image of a trashcan on it. Click on the trashcan to delete the message permanently.
You can select multiple messages this way and delete them all at once. Just be careful. Once deleted, I cannot undo it.
I hope this helps.