You can try contacting the manufacturer. If the combination hasn't been changed, they may provide you with the combo for a fee once you prove it's your safe. If they don't want to deal with you, you can get a locksmith to request the combo. If neither of these options work, check to see if there is a layman group of safe and lock pickers in your area. They might take the project on for the challenge. Good luck!
I would recommend taking the deadbolt back to wherever you purchased it from and exchanging it for a new one. It sounds like you got a defective unit.
Just so there’s no confusion, this website is a general question-and-answer site for anyone who needs help fixing something. It’s not the customer service website for the manufacturer or retailer you got your deadbolt from. I do not represent the manufacturer or the retailer. I’m just a random guy on the internet trying to help out. :)