Landline doesnt ring no ringer on incomming calls

More common of the two reasons your handset telephone can’t be heard ringing, is that there is actually an issue with the ISP side of the network. 

When your telephone rings it's supposed to send AC voltage down the line, and if the voltage isn't meeting the required level. it won't sustain enough voltage to trigger your handset to make the ringing noise. Or in-fact, depending on how much voltage is being sent, it can result in low ringer volume; meaning you can still hear it but really low.

Many telephone service providers tell their customers its a faulty handset, and their volume button isn't functioning correctly.

Yes, I understand you can still make and receive calls, it's because it uses DC voltage as opposed to AC voltage to make the phone call.

The second reason is that, depending on your in-home wiring and if you have more than one phone point in your home, your internal wiring can be causing no ringer noise.

I'd say if you have more than 3 sockets in your premises, the best way to improve internet speed and telephone reliableness is to disconnect all lines except the wall sockets your telephone and internet connection is using.

As a technician, I actually repaired one family's internet connection with your exact same ringer issue by disconnecting all the sockets in the house from a star-wired configuration.

So, listen, if you are residing in an older house perhaps, it might just pay to engage a telephone/internet technician to either rewire your home and replace your sockets, and if the problem still exists, engage your ISP for further action.

TIP: Even if you're connected on the NBN network and using a VDSL modem, the same theory principles are involved when your handset is plugged into the FXS phone port of your router.