Welcome to BBB Itsxtruex3! Sorry for the late reply, but you should be able to block users from IMing you on your phone by doing the following:
- Upgrade to AIM 1.0 if you haven't already here: AIM | Chat, Share, Connect
- After logging into the new AIM client, click File>Settings and click on the "Text messaging" tab on the left.
- Click "register a mobile device", enter your phone number, click "Send Code Now", and enter the code you receive on your cell phone.
- A new bar will appear for your confirmed cell phone number. Click "Edit" next to that number, and simply check "Block users from sending messages directly to <your number>".
When a new screen name IMs your phone via text for the first time, there may also be a "cover text" from AIM with instructions on how to block texts from that screen name only, but that may have changed since the upgrade to AIM 1.0.
Good luck and let us know if this solves your problem!