HTC desire bravo sim card is always ejecting I have to hold the card in place while using the phone otherwise it pushes itself out. When troubleshooting the problem, being as gentle as possible by the way, it clicks into place but doesn't catch and is pushed out by the spring lock.
Sounds like the micro SD card slot is physically broken on your phone. You need to take it to a technician to fix it, or return it if it's new or still under warranty.