I don't own one but before my current business I was a service manager at a GMC dealership, which of course is basically the same as Chevy.
This sticking pedal is usually caused by one of two things, the most common is a dirty throttle body.
It happens not just with GM's but other makes as well. Carbon builds up inside the throttle body and causes the throttle plate to stick, which transfers to the pedal.
It's easily corrected by cleaning the TB which you can have done at the dealer or most any other reputable repair shop. Estimates will vary but expect between $30-$90 depending on if they do a full fuel system service or just clean the TB.
The other cause could be the throttle body itself, GM had a few issues with some early ones that were defective and causing the pedal to stick. The ones that were defective were identified by the serial number on the TB, your dealer would have to diagnose and determine if it's defective as per the technical bulletin that was issued.
However, like I said chances are it's just a dirty throttle body, they do require periodic cleaning. My personal opinion is GM should list this in their list of maintenance services, but for some reason they don't, nor will any of the other manufacturers.