My friend you have a misunderstanding of the network. Reason Apple & Bell as well as Telus removed the 3G option on the iPhone 4S is to prevent confusion mainly.
Bell/Telus/Virgin/Koodo all share one network (however Bell & Telus do have their own towers but are shared between the two)
Bell/Telus/Virgin/Koodo do not have a 2G Network that is GSM, they do have the CDMA network but the iPhone 4S cannot fall back onto it as the iPhone 4/4S Sold in Canada are the GSM Versions only unlike in USA that are CDMA(iPhone 4 on Verizon/Sprint) and CDMA/GSM(iPhone 4S on Verizon/Sprint) and GSM Only (AT&T <- Same one we have on Rogers/Telus/Bell/Virgin/Koodo/Fido) versions. (Please do not go buy a iPhone 4S that is from verizon/sprint as it will not work on Telus/Bell)
What you want to do since You still want to be able to send text messages and receive calls is simply turn off "Cellular Data" and your 3G icon will go away leaving you with just voice and text service.
If you noticed on your iPhone 4 since you owned it, the moment you turn off "3G" the network gets lost on Bell/Telus/Virgin/Koodo again providing you proof that Bell/Telus/Koodo/Virgin only have a 3G HSPA/HSDPA(HSPA+) Network running on 850/1900MHz and not EDGE/2G.
Only Rogers/Fido in Canada have a 2G/EDGE network where if you turn off 3G you will have the "E" icon appear and you will still have data functional.
Please Note:
- Bell Mobility Owns Virgin Mobile
- Telus Mobility Owns Koodo Mobile
- Rogers Wireless Owns Fido and Chatr Wireless.
Networks with 2G:
- CDMA = Bell/Telus
- GSM EDGE = Rogers
3G/HSPA+ GSM Networks on 850/1900MHz Frequency (Meaning you can take your iPhone 4/4S in Canada to any of these carriers if it is Unlocked):
- Rogers, Fido, Telus, Bell, Virgin, Chatr, Koodo
Traveling to USA?:
- AT&T(Straight Talk, H2O Wireless, Red Rocket Mobile etc which are not owned by AT&T but use AT&T's network to provide service) will get you 3G on your iPhone 4/4S
- T-Mobile has a EDGE/2G Network Compatible with all models of iPhone.