I read a review while searching for the number and it said that Dabs had a number on their site I have looked and I know you have and their aint no number on their site so I doubt they must have taken it off and it seems the only way to contact them is by e-mail very convienient for them.
I can remember trying to contact a newspaper, I think it was the 'Times', directory enquiries said it was not listed! Many companies do not have operators to answer the phone these days, and don't want people to stop work to answer the phone. The people who do need to know the number will dial directly to the extension they want. It's the way of the world.