I was a Vodafone customer when I was contracting. I bought (OK cheaply) a PCMCIA 3G card which was the bee-knees back then. I was having issues and went through to technical support, once I'd got through 4/5 layers of idiots. The tech guys were no better, they hadn't got a clue. In fact one of them said, "You've got a better idea than us!" I was trying to run some obscure software which required specific ports to be active. They kept insisting they do not port block (even though using port scanners I could prove they were) and they were absolutely insistent that they don't use a NATs (Network Address Translation), which again I disproved by showing them my assigned 10.10.X.X IP address.
They gave up in the end, refunded a 6mth old PCMCIA card and lost a customer forever. Went to local shopping centre, visited the Three shop, £50 saw me with a usb dongle, which worked faultlessly. I didn't even check the network settings, it just worked.