Opodo complaint: Website not clear

We booked a flight from Athens to Corfu through Opodo where the options for baggage allowances were not explained. The tickets we booked had “hand baggage included” and then asked to add a check in bag for extra £30.
We did not want to have a checked in bag so we didn’t add it and continued to the payment page.
Turns out at check in that the airline we will fly with have different types of fares with different handbag allowances – now we are forced to add 2 extra check in bag for €21 each because Opodo didn’t give us the clear explanation of what hand baggage was allowed with our ticket (either personal bag OR carry on bag.. and we have both).
The guy at the customer support line told me to check the airlines policies on hand baggage when I received the ation of my purchase. 1) why do I use your website to get the best prices while making you earn money and have to go to the airline’s website to check what is meant by hand baggage? 2) how does it make sense for me to know which fare I’ve booked when I already have purchased the ticket and received ation from the airline?!