Why won't my unlocked Rogers Torch 9800 work with T-Mobile?

I have an unlocked Torch 9800 (Rogers) and I bought a SIM from Ultra Mobile in US which works on the T Mobile service. I received a text from Ultra telling me the service had been activated but I can't make calls or send texts. Can anyone help please.

Thank you

Love to help, but that's a carrier issue. There's no love lost between BlackBerry and T-Mobile, but you should get phone and text with a working SIM. Just going to have to work with customer service, till you get some.

Good luck! :)