I am new to Icloud and inadvertently downloaded an itune apparantly but cannot find it but have been charged £15

I have a new Ipad on which I joined ICLOUD and apparently I have downloaded an ITUNE but dont know what it is and where it is stored, the only reason I know this fact is that I received a receipt for a bill cor £15. can anyone help this computer illiterate to sort this out I have sent ICLOUD an email explaining this but have not had a reply yet.

Poshmalteser