Unable to change Country

Dear Whomever this may concern,

I have recently travelled to another country for study purposes and I wanted to change my accounts country/region. However, due to the fact that I have 4hkd apple id balance leftover in my account, appstore stated that I could not change unless I spend it all. This then led to another issue as nothing in the store costs less than 8hkd. Hence, I decided to upcharge my account with my visa debit so that I could perfectly spend all my remaining apple id credits so that I could change my country/region. However, when I tried to upcharge my account, they kept rejecting my card and instead recommended me to reach out to itunes support on every occasion. Therefore, I would like to inquire upon this issue and I hope that it could be resolved as soon as possible.