Nokia Beacon 2 locked by Metrofibre not to be compatible with other non Metrofibre Nokia Beacons

Beacon 2 - Cant buy additional units for Mesh Wifi Been with Metrofibre for a while, using them as my ISP. I have a Nokia Beacon 2 router. I needed an additional Beacon to add to my network setup to assist with dead zones in my house. I was told that I need to add a monthly R100, 00 to my subscription to get an additional Beacon. There is no option to buy one from them. This I find unacceptable business practice. As they have also locked their beacon not to be compatible with any other Nokia beacons that is available in the market, to force customers to subscribe to theirs.

All I need is to be able to extend coverage of my wifi to the house without an additional unnecessary expense. why cant this be made possible. I can do it with ordinary wifi extenders, but not with Nokia Beacon for Mesh wifi. This is disappointing business practice.