Did I just get a freebie ?

[CAL2]

Hi, original we wanted to fly world traveler plus out and world traveler on way back, but had decided to book both ways world traveler and pay to pre book seats. I was on manage my booking today when I saw an upgrade deal. so started booking it using my phone, I got all the way to payment and nothing happened. I phoned BA and told the man what I was trying to do, he put me on hold,when he came back he said he had tried a couple of times but couldn't do it and the reason was all the seats had gone. I thought ok, but thought it was strange they were advertising it if there were no seats, so me being me I tried again, what I had done was put visa instead of visa debit in, altered it and it worked. So upgrade done now I wanted to book my seats, phoned back, same person I think answer, he said he need to know the row and letters of the seats I wanted, fair enough, asked how I find the seat plan, he explained. So back on my phone, got up seat plan had loads of choice and had prices of how much the seats were, me being a bit dim thought that's good I'v already paid £58 pp for the seats in world traveler so no extra to pay. Went ahead and chose our seats its said payment waiting, thought it was odd, but thought maybe I have to get money already paid on previous seats transferred over. so back on the phone I go again, same man, explained what I was doing, his reply madam these are better seats you have to pay the price shown for the seats, my reply no I paid when I booked before just need to book the new seat, now he must be fed up with me keep calling and explains to me no madam the seats are £105 each the price shown on the booking is the balance remaining! the tone he used got my back up, so I said where does it say that on the booking form?, silence from him, then he says is there anything else I can help you with, so I repeat my question. He said I'll just put you on hold. after a few minuets it was obvious he wasn't coming back lol. I put the phone down and tried again on my to book seats online, willing to pay the difference but got as far as payment and couldn't get any further. So you guessed it back on the phone, thankfully I got someone else. She went through it with me and then said that's £125 to pay, nooooooo its £90 I have it right here in front of me, it just wont let me pay for it, I was put on hold, she came back and said all done seats are booked can I help you with anything else?, me, er yes payment I still haven't paid, her reply no payment you already paid before !!!! . I said but it's saying I need to pay £90 to book those seats, she says, no its all done.