Getting Touch ID Back

It's not a matter of reprogramming Touch ID. If the front screen was replaced with an non-Apple original screen, the front screen will need to be replaced with an authentic screen. They typically won't service a phone with visible damage. You purchased a phone which is damaged, and it's not going to be a simple or likely inexpensive fix.

If it was repaired by a 3rd party who damaged it (as they clearly did) Apple will not attempt to repair it. There is no way that Touch ID can be restored on that phone.

Touch ID requires that the button be physically matched with the logic board and the cable. It’s not a matter of software pairing. The only way to fix it is to replace both the button and the logic board, which would cost more than a new phone.

Lawrence Finch wrote:

If it was repaired by a 3rd party who damaged it (as they clearly did) Apple will not attempt to repair it. There is no way that Touch ID can be restored on that phone.

Touch ID requires that the button be physically matched with the logic board and the cable. It’s not a matter of software pairing. The only way to fix it is to replace both the button and the logic board, which would cost more than a new phone.

I don't know if it's a matter of "software pairing" but as far as I've understood it, Apple can pair any OEM home button to any CPU. And it can (but doesn't always) get "unpaired" when someone attempts a fix where they're physically disconnected.

However, Apple is certainly not going to put it on their rig to do the pairing if the case glass is damaged. Also - it sounds like the OP may be in a country where Apple's available services may not be the same as in other parts of the world like the US.

If the case glass is damaged, Apple simply doesn't offer fixes for anything else. They'll either return the device unrepaired or will require a complete exchange for a service replacement.

Also - where's your location? In many parts of the world. Apple doesn't have any actual repair or perhaps limited repair. To pair a home button to a CPU requires use of Apple's proprietary "Horizon Machine". Often this will be done as a complete swap, although it might be done as a price commensurate with doing just that repair. The value proposition for Apple would be that they have a device that they can recondition or reuse for parts to make new service replacements. In many parts of the world it just goes back to the factory and then gets fixed up for another customer to use as a service replacement.

OK. I wasn’t sure what the R stood for. My first though was rupees, but then rand made more sense with the price.

If it’s an aftermarket screen and the original home button has been reused, the process could have unpaired it when it was disconnected. It’s supposed to be a security feature.

I don’t know exactly what they’ll do. Apple and AASPs have been known to fix bad screen assemblies with OEM ones. As far as I know, the complete screen assembly comes with a new home button, which would then need to be paired with the CPU. However, you stated that the case back is damaged. No Apple Store or AASP will do any service on it. That’s only “repaired” with a full service replacement.

Take the phone in for service.

Nope.

Only Apple or an authorized service center can properly repair the phone, if they will touch it because of the possibility of unauthorized tampering and use of third party parts.

Let's not to forget the OP says the back glass is broken, which can't be replaced and Apple is unlikely going to offer service on a phone in that condition.