Since you've just done it, give it at least 48 hours. Often the problem is the system updating your account, rather than it accepting or processing the payment. A lot of the time, simply waiting 48 hours is the fix.
One correction, Rogers maxes out Roam Like Home charges at $50 per bill in the U.S., or $100 per bill in other supported international destinations. Just be wary of your trip straddling two different billing cycles, or of you going over your data all...
Most dual-SIM phones only support 2G for one of the SIMs. Some phones (all dual-SIM Windows Phones, and some Android phones) let either SIM slot be the primary SIM, and it's a software toggle. It seems that's the way the OP's works, from what was s...