I received a response from Peter Pan (which tells me my written letters arrived at their destinations!)
In a nutshell, their response was that they apologize for the rate discrepancy, but that they do indeed have the correct price on their website and that they will communicate with Greyhound about advertising the correct prices for Peter Pan routes in the future.
A very polite way of telling me that their rate is the only rate that matters. I can respect that, and I am very thankful for a quick and professional response.
Now, let's wait and see what Greyhound has to say...
