Just saw this, been out at a ball!
You poor thing, it sounds like you're having a rubbish time of it. [hugs]
If you have been fitted and it doesn't fit, I would be utterly shocked if they don't return it/exchange.
I'd be a bit concerned about the central gore not sitting flat - like SF I have a couple of half cups which don't sit quite as flat due to the style, but I just googled the one you bought and it doesn't look like a candidate for that. If you are conscious of it then I'd say it's probably not the right bra for you. She should really have tried different bras - a good fitter should make sure they find the right bra for you, not just the closest fit in the one they have to hand.
It wouldn't be unheard of to need a different size in different colours of the same bra - both due to them being made slightly differently and because there is something to do with black dye that means the fabric behaves slightly differently so tends to be a fraction smaller (I think). Can't remember the technical explanation but it's something I've experienced several times. She should really have got you to try each one, just selling you the same bra in 3 colours without checking is a bit lazy! Never mind getting the wrong size for two of them.
I've never tried the bras you bought, but it sounds like you know how a good bra should feel. It might be worth you shopping around and trying some alternative brands. Personally I don't think really cheap bras are as good, but that's just me. However, I also know there are some brands which I can't wear - Panache and I do not get on, they are totally the wrong shape for my breasts. Freya on the other hand are great, as are Bravissimo own brand.
Oh, for future reference btw - Bravissimo are excellent about returning faulty bras. I had one which I had barely worn (got pregnant about a month after I bought it) and when I started wearing it again the wires popped out. By this point it must have been about 18 months old. I emailed their customer services and they agreed to exchange for a different one (original was discontinued) and they even replaced the pants too.
I really hope you have better luck tomorrow.