i cancelled a subscription but i still cant download apps

Either try a different card and see if that's accepted (when you have a card on an account it has to be a valid card, even if just trying to download app updates or free apps), or see if you can remove the card (that would let you download free items and app updates) : Change or remove your Apple ID payment information in the iTunes Store - Apple Support

You are only charged if you purchase something.

When trying to remove the card you are following those instructions i.e. you are just logging into the account ? You won't get the 'none' option when trying to download something. If you are following those instructions, do any of the scenarios linked to from that page apply ?

Why can't you download them, what happens when you try ?