FNB upgraded my account without my concern

I feel so disappointed with FNB and feel like switching banks.they just decided to upgrade my gold cheque account (monthly payment of R109) to private clients (monthly payment of R399) without my concern.they just send an sms saying that my private clients card is on the way and i must collect it from the branch.when I called them to downgrade me back gold because I didn't authorise any upgrade and will definetely not afford R399 a month,they said downgrade will take 7-10 days whereas in the mean time i was being charged as a private client.that unauthorized upgrade and downgrade all in all charged me +R400 which was deducted in a period of 10 days.they keptcharging me for this service even though i told them that I didn't authorise any upgrade,I feel unfairly treated for being held accountable for something that im not responsible for,why Fnb they don't investigate further and find out why was i upgraded without my concern before they can continue charging and charging me?I really need my money back...I don't even meet minimum requirements to be a private client..