FNB Pathetic Lack of Customer Service

FNB has repeatedly over debited and debited incorrect amounts from my fiance's account (which I am linked to) - no matter how many times we've called in and sent emails, we receive no feedback - besides collections consultants calling in to say we haven't paid - all the while they're debiting multiple times and amounts that they shouldn't be! Which has resulted in us racking up collection fees bc of our cellphone contract debit order bouncing! Utterly flipping disgusted with this pathetic lack of service!!