@Kikanada You're very welcome - though I wish I had better news for you.
Please come back and let us know what you find out in the end.
Possibly...but a hard reset usually takes care of any software issues. My money is on this being hardware-related. Hopefully it'll be a cheap fix...
In addition to @7789849803's thoughts, double check the phone did not set itself to 2G cellular service. If your phone is going to work it must be set for 3G. Rogers still operates a 2G network.
@Luddite It`s 3G allright. I found some jailbreaking tutorials but would rather not do it. WIll try downgrading to a previous iOS maybe. I really just need it to call & text.
Just to be clear that 3G is found under Voice & Data in Cellular settings (in iOS 9 anyway)? Jailbreaking should not be required.
Also, send an email to PM describing the problem and check out this post: iPhone 4/3GS/3G. They take up to 2 days to respond so you can also keep checking this forum for ideas.
BTW: How long can you survive without service?
I respectfully disagree with @Luddite about the need to email PM support. Such contact would only create confusion and take away from PM's precious few support resources.
It is quite clear that no one at PM can do anything about this situation since it is decidedly related to one particular device which was not purchased from PM.
@Kikanada, is the phone already jailbroken or was it in the past? Sounds like the baseband maybe be screwed up as if it's running iPad baseband which a lot of 3gs jailbroken devices did it will have issues getting network service.
I had an old i3gs with network issues, no service and I had to downgrade the iOS and baseband. There are tutorials online for it.