I had the EXACT same thing happen with 10v I bought from the US outlet last month. After spending 45 min. on phone with India, I finally managed to get them to send me the 5530 card after MUCH, MUCH frustration. The tier 1 support is absolutely clueless about the product they're supporting. All is complete now. However, they charged my account for the card, and sent a return label to return the defective (non-exsistant) part.
Luckly, I make PDF's of every page during the order process, and like you, the WWAN card is listed on my invoice. Just a word of caution for anyone purchasing a 10v listed as having WWAN from the outlet, the 5530 module will prob. not be in the system when you get it, even though it is listed on on the spec. page. Luckily the PCIe slot and antennas are.
Sure I'll have to spend more time sorting out the +$200 charge for the part when the time runs out to return the defective (non-exsistant) unit. Dell's automated phone system has already been calling saying they haven't rec'd it yet. Hope you don't have same problem.