Duplicate transaction on my FNB account

Hi, I’m very disappointed in FNB as I have been their client for the longest time. I keep on having card transactions being debited twice and I was told to do a dispute for those transactions. Problem is this problem keeps on recurring and when I speak to FNB I’m told I should wait up to 7 days. In the meantime I can’t use my account. I’m very much inconvenienced because I can’t but groceries or petrol or anything I need. Basically I can use my account as it’s sitting with a negative balance due to duplicate transactions. Now when I call as soon as I get verified the call cuts. I’m aggrieved I want to close this bank account.