poor service at cape town BA ticket office

we recently traveled to the UK 5 passengers i had gone the air port in late December to book and pay for our 5 return tickets 3 adults and 2 children i was offed a good price for the tickets so i took them my wife asked the sales lady about the luggage for the kids her response was that we all allowed to have a hand luggage and a cargo bag except for my wife she was told that she can carry 2 bags in the plane with her for our son as he is baby . all went good up the the point that we were checking in at the desk i was told that the ticket that i was sold only had allowance for hand luggage only so i went to the sales office that i purchased the tickets from and spoke to them they called around and told me it was sorted i asked will this be an issue when i return after my 18 day holiday i was told NO its all sorted .

when we got to the air port in the UK to check in our bags to come home the same problem again so i had to pay to bring the sames bags back with me 45 pound x4 and 1 bag was 65 pound i had no choice but to pay this , when we landed back in capetown i went to the desk where i purchased the tickets fro i was told to do it on the WEB so i said ok and off i went i looked on the web and found no tab for bag refunds only lost bag claims so i tried calling the office number but no answer to this day ! i would like my nearly R5000 back that i had to pay after i was told that it was all sorted