I need help on Pokemone Platmun for the DS?

I have 7 badges i have defeated Team Galactic and i have the Pokemon Giratina. But Sunyshore City is still under blackout. I can’t get the National Dex cos Rowan won’t give me it, i can’t find all the Pokemon cos some are located after Sunyshore, and i don’t have the cheating thing.
I really can’t figure out what to do, i’ve been to all the lakes, and tried to catch the Pokemon but they don’t like Poke Balls. Lol.
Where do i go next?
I tried to go to Pal Park but its not finished yet!
I’ve been to Prf Rowam! He says if you see Cynthina give her my wishes.

Go speak to professor Rowen