I'll be heading down south in a few days and would like to use my phone (Nokia 6121) as a modem. I've been told by someone (on here, I think?) to call 678 to get it added quickly and properly. What I'd like to know is how long it takes to become active. I don't want call and be told, "oh, that will take 4 working days" or something like that, but conversely I don't want to pay too long for something I won't be using.

I'm thinking the 100MB data plan might suit me, but if I want to upgrade it (say to 512MB or 1GB) can that be done quickly and easily, or am I stuck with 100MB until it runs out, or can I add more?

I'm on account, not Prepay.

Thanks