Invoiced by error (?) on PREMIUM Itunes Store 17.00 chf/month

I am getting invoiced of CHF 17.00 / month

for PREMIUM iTunes Store since long. (Mote than a year.

I don’t know what it is

and don’t think to use it. Please explain.

And pls tell me how I could get this cancelled ?

Thank you :

ref «  ITunes Store premium »