Possible chargeback

My phone’s apple account has recently been disabled in the apple iTunes Store which makes me unable to download/update anything. I watched a couple videos and they have said to sign out and log back into my apple account, so I did and it’s still not working. I went into my payments and saw that a few prescriptions have been canceled besides one, I remembered that I have used the app and then canceled the prescription a day later or so. I’m pretty sure the issue is a charge back but do you guys know how to fix a charge back?