The problem in detail:
My Galaxy S II has suddenly lost it's ability to connect to my wireless provider (Bell Mobility). I've checked in Settings -> Wireless and network -> Mobile networks: There is just the message, "Insert SIM Card...", even though the SIM card is in there as it has been all along. Where my SIM card data should be displayed, in Settings -> About phone -> Status shows Service state as "Out of service", Mobile network state as "Disconnected", and My phone number, Network Mobile network type, IMEI and IMEI SV as "Unknown",
I have tried removing the SIM card, inspecting it for visible defects, etc, even wiped it's contacts, etc, but to no avail. Lastly I've taken the SIM card and placed it into another phone. The other phone read all my SIM card's data, and connected to my wireless provider service no problem.
Therefore obviously the problem has nothing to do with the SIM card, so I can't count on my provider (who I bought my Galaxy S II from) to provide support in fixing the problem - unless I return the device, utilizing its manufacturer warranty (which is a last resort, since I'll have to ship it clear across the country at my own expense, to Samsung's North American/Canadian customer service center, and wait for the indefinite duration...).
Thanks in advance for any helpful information/experience/advice/suggestions/etc. towards resolving this.