Refunding money from Apple ID by accidentally disputing too much on it.

I wanted to deposit a smaller amount to my Apple ID Balance. Accidentally the amount went up to 100+euro's and I want this amount back on my account from my banking app. I cannot enter/tap the amount at Apple Support to request a refund because it is not from a subscription like a provider. I know I can't do this by myself and need to get help from iTunes or Apple Support but I doesn't work. is it best to call apple support?