My after-school Grade 6 class is the most challenging.  The students in the class don't like to do anything.  If I use games, they complain it isn't useful and just having fun or "playing games".  If we use the textbook, they don't want to do that.  They just like sitting around and chattering with each other throughout the classtime.

Any ideas to get the class back on track?

BDB

The kids are going to whine regardless of what you do.  If the class isn't free talk and phone games they aren't going to be happy.  So forget about what they think and plan the class however you want. 
Personally whenever I teach extra classes or after school stuff I try to keep an even mix of studying and games.  Always do the work work first and the sooner we get finished the sooner we can play a game.  That helps to keep the kids focused and they gang up on each other if somebody is slacking.  I always try to keep the game related to whatever they just learned to help cement the new material and should keep the complaints down. 
You just gotta find a groove that works for you OP.  good luck.