You may have gotten an answer, since it's been a month, but this happened to my sister when she purchased stuff recently. The songs did not download after purchase and could not be found in the purchase history, but the funds were removed from her playstation account. Needless to say I went to the Singstar viewer app and went to purchases and cycled through all the different topics, letting it access the network, and then moving on to the next. Eventually I made it back to Songs and the newly purchased songs appeared and I was able to get 1 or two in the queue to download and then the new songs went away, but the lights on the front of the PS3 gave me hope. I cycled through again and they appeared once more with the downloading symbol. I continued the cycling trick until I had managed to download all of her songs. Once in the game the new songs updated and were added to the library.
Please note that not every time I cycled through did the new songs refresh, sometimes it took 3 or 4 cycles before they would appear.
I have a feeling this is related to the store refresh and that they'll eventually fix this as well.
Hope this helps
