When I'm going around 60-70 mph and I let go of the accellerator, the RPM stays at around 3000 and it seems like the gear doesn't shift down until around 50 mph. I can hear the transmission staying in the high gear. The only way that the RPM goes down is when I step on the accellerator really quickly again.

Is this a problem with the transmission itself or a malfunctioning cable or something else?
I don't know too much about transmissions... Please help!

 

i would do a quick check of the fluid level see if everything up to mark...

check the throttle body cables make sure its not over tightened...

last but no least bring in the car for a check of the tranny which will cost a few hundred...