This Brunnels library works perfectly here, so I suggest you keep trying.
The PWM frequency is set/stored inside the PCA9685, so don't change PWM frequencies of the Arduino pins.
They have nothing to do with each other.
I think you're using the wrong commands.
You have to use the new PCA9685 library commands.
Here are some.
whiteDrv.setFrequency(200); // without the PWM
whiteDrv.setChannels8bit(0, 15, 0); // turns everything on the "whiteDrv" board off
whiteDrv.setChannel8bit(3, 255); // sets output four (ch 3) to maximum
whiteDrv.setChannels8bit(8, 11, 200); // sets output 9 to 12 to level 200
Note the Channel (one output) and Channels (range of outputs)
The 8bit commands (value 0-255) use the 12bit log lighting lookup table.
There are also direct 12bit commands. And RGB commands.
You can also read the value of a channel, e.g to feed/update a web page, or print to serial monitor.
I never used this, but I think it's "whiteDrv.getChannel()
Hope this helps.
Leo..