FNB makes it difficult to escalate matters and resolve my query *****ed*

FNB has really shown me that banks are a bunch of ******. I have been trying to get funds reserved from my bank account paid back into my cheque card with no success. Called cancellations, customer care and even tried disputes department. Last straw was when I was placed on hold for 34 minutes by an *********** lady whom I heard carrying on talking on the other side with her colleques. All I need is simple; pay back my reserve funds so that they reflect in my bank account. Don't tell me to fill a dispute form because already done that, don't tell me to contact the company that reserved the funds because your cancellations department already told me the error is with FNB. I hate FNB service with passion and wil be closing my account after this. Sent emails to every department and even social media but nothing. Was told to wait 7 day's but have been waiting from the 2nd August with nothing. My cheque card is in a minus and fnb sent me an sms threatening to take legal action against me when it's their fault.