It was really difficult for me, too, when I was setting up 3 again. Sometimes it took a while for my stuff to be recognized by the Sims 3 store (same account, obviously) and some things I just had to buy again. They were polite and good with the EPs themselves, but Origin support was not really much help for store content. I am not sure if it has it's own support, I did not see it, but would recommend looking there.
Otherwise, I do not know if anyone or anything unofficial can really help you. Beyond purchasing it again, which I did not really want to do either. My damage was much more minimal, though, so it did not make sense for me to quibble over it too much.