Say you're in a rock band and you cover a Beatles song, but you change a guitar riff to make it sound a bit different. Just because you do this doesn't mean it's your song. The Beatles wrote it and put a copyright on it so others can't steal the song. When dealing with survey services you might come across the same thing.
Some companies might legally own survey data. You can use the data as research and examples for your survey, but you can't call it your own. Before you sign on with a survey company find out if you are just renting, or you can actually own your own data.