Changed my tariff new modem is sent what to do with old one

[EfeEngin85]

hi community..

I have changed my home vodafone kabel from 400mbit to 1000mbit what should I have to do with old modem ?

[Stephan]

Hi EfeEngin85,

if you have changed your tariff and received a new device for it, you must return the old device. You have received a letter with the return address for the new device.

Gruß

Stephan