Reddit mentions of Gossard Retrolution 1/2 Padded Bra in Black 38G

Gossard half padded styles (Retrolution, Colour Clash) are exactly where you're looking for. They've been discontinued for a while so finding them is a little bit tricky. There is one in black on Amazon, and Canadian Amazon too. And a pink one on eBay.

And actually horizontally seamed bras are the worst out of all bras at providing uplift. Really. Vertical and diagonal seams are what you want. You may like Freya balcony plunges, especially Patsy and others that share the cut, they have a slightly pointed shape but they give much better uplift than any horizontally seamed bra can.

Also, are you maybe wearing the bras too low?
http://i.imgur.com/wuKovXy.png
http://brasandbodyimage.com/2012/09/05/putting-your-bra-on-properly/
https://www.youtube.com/watch?v=ks6BCcsvrrs