I needed to do it some months ago and got approved in less than 48 hours but as some others said, maybe they are very busy and it will take a bit longer. Keep us informed how it go and I would doublecheck with the live agents if you can participate in the promotions.
The usual time in most cases is 48 hours but sometimes they can take more then it to verify all the details and then approve any transactions but if there's more delay you can always contact the team to clear about it and have confirmation from them.They have to follow all the AML guidelines in accordance with verification of KYC documents so it there is rush it can take some time.
I think 48 hours is more like "if all goes according to plan" situation, and even in that it takes 24+ hours for sure, and less than 48 hours, there aren't that many cases you get it back in a few hours, that just doesn't happen.
However, if things do not go according to the plan, then we are talking about a situation where it can easily take longer than 48 hours, and until what is wrong gets figured out, it could take as long as a week. I am not against these, I had it happen to me before and I was fine about it for two reasons. First of all duelbits is a trusted and well liked place, secondly I did not do anything wrong so I had nothing to worry about. Combine those two, and you know there is no problems.