icloud problem please help me

So when i had to fix my iphone the people at best buy set up a new icloud account for me. I only know the email and nothing else. to make matters worse it wont accept my birthday. the guy at best buy made the other stuff up and we both forgot and no one wrote it down. i cant figure out a way to get into the account. it has all of my pictures and everything. the only thing my phone has now is my contacts. all my apps are backed up to the icloud as well.