Does Blackberry messenger work in any country?

My BlackBerry won't connect to the internet, receive emails and BlackBerry Messenger does not work?

• I recently changed the sim card of my BlackBerry 8520 from an 02 sim to a giffgaff one. Since then, the phone has been unable to connect to the internet or use any data. The phone is also permanently stuck on 'gprs' mode and will not connect to a 3g network. I am also unable to log in to my BlackBerry ID. I would appreciate opinions on this matter, thank you!

• Answer:

  Things to do (in my opinion): 1. Try to put the O₂ SIM card back in your BlackBerry device and check whether it's now able to connect to the internet and you are able to use all the BlackBerry service (BBM, Log in to BlackBerry ID, etc) like before » Please make sure that both your O₂ and GiffGaff are registered to the BlackBerry Internet Service. If the problem persists... 2. Try to contact the GiffGaff provider's Customer Service and ask them for help. If the problem stay still... 3. Try to check whether your BlackBerry device is locked by a provider or not. You can ask about this to the place where you bought your BlackBerry device. (A locked-by-a-single-provider BlackBerry device usually sold as one in a bundling -BlackBerry handset with a SIM card already- and sometimes there's a provider brand logo stamped on the BlackBerry device) If the problem still persist (again)... 4. Try to check whether your BlackBerry device got an error/bug(s) in its device software. For this one, you need to check your BlackBerry device software version by typing: "myver" (without the quotation mark) anywhere on your BlackBerry device, then check on the internet, what's the latest version of the BlackBerry 8520 device software. If your device software is not up to date, you may need to upgrade your BlackBerry device software (newer device software usually contains a lot of bug and error fixes, etc). Hope one of the solutions there help you solve the problem.