@GermanAizek
AFAIK
IMEI authenticate the hardware to help fight against stolen devices.
The SIM card is what authenticate the user to a network (it's in the name: Subscriber Identity Module).
So even if you would fake your IMEI you wouldn't fake your SIM hence being tracked.
And if a network is not able to identify (and track you) they will not grant you any service...
If one don't want to be tracked, they should avoid cellphones.