Not able to get any assistance on Private Banker when interest is overcharged on credit card.

My interest on my credit card went from R1000 beginning of June to R2500 in July ... the outstanding amount did not increase!!! This is impossible as the national rate came down. Now I tried to speak to someone at Private Wealth client service. I tried emailing last week, the query was closed without ANYONE speaking to me. Emailed using the address in app - "Your message wasn't delivered to *** because the address couldn't be found, or is unable to receive mail." I called, the line literally went dead. I tried the in app chat, been 30mins - no one rep****. When Elelloang rep****, she just disappeared again, WITHOUT ATTENDING TO MY QUERY

Seriously FNB - this is ridiculous...