Ahmed lied and said he would organise an English speaking guide. His guide did not in fact speak a word of English - or know where to take us. When we complained, Ahmed denied he had ever agreed we would get an English speaking guide - although we had it in writing - and became threatening on the phone. It completely ruined our trip to al ula. We were unable to see any of the sites as the 'guide' did not know how to get us tickets. He  also knew nothing about the history of the area so even with Google translate we got no where. We paid $1200 for a two day taxi service that we could have bought for $100.  Ahmed will ask you to pay in advance, so you can't refuse to pay when things go wrong.  I would strongly urge everyone not to deal with this man. He is a con artist, who knows he is ripping people off. I suspect the good reviews are fakes.