O2 Music Paket/Telefónica Germany 1 😡

month ago i paid almost 15 euro for O2 Music Paket/Telefónica that i didn't ask to subscribe i unsubscribed month ago and as i see this month i have to pay almost 5 euro for the same service this is not fair i want my money back and i want know when this service end because i don't want pay for it for ever