|See this video:|
You have probably pushed the USB jack out of the tiny circuit board it's connected to. It's unlikely you can fix that.
Even if you did fix that, the case was probably not designed to be opened. If you want to continue using it, you will probably need to do something such as wrap vinyl electrical tape around it.
I recommend you throw away the external enclosure and buy yourself a new one suitable for SATA drives. An external enclosure that supports USB 3 or eSATA or either of both types of those connections will yield you the best max data transfer speeds.
I recommended Vantec models.