I had a very bad experience with expedia.ca customer service regarding a "airline hidden fee issue"
Long story short we booked an all inclusive trip but on the way home were informed we couldn't check our baggage (1 bag per person - All under weight) unless we paid $15.00 USD per bag.
We expressed our displeasure to expedia.ca about there lack of communication regarding these fee's and the fact there was no mention of it in our booking confirmations etc...
The customer support person was rude and basically said tough luck and there is nothing we are willing to do to help you.
They lost 4 customers already and hopfully other will read this and come to the same concusion.