If you have partitioned it, then copied new files to the drive and then deleted the partitioned then your files have been deleted as well. In your text you stated than you copied files and then you said you deleted the partitions, but haven't added anything on the disk yet. Kind of confused on that part, but from my understanding once you have deleted a parition everything is deleted as well.
Delete partition indeed will take only a few seconds .. with any kind of partitions tools (windows disk management, partition magic, etc).
However there are some recovery tools available on the nets, some freewares too. I used Easy Recovery once, like couple of years ago (on Win98/2K era). I'd never done this again, always backup everything before messing with HDD