Shocking service received from Standard Bank regarding my Credit Card

I have a standard bank credit card. T & c's state that the card is 55 days interest free. So I made a purchase 27.10.2018, assuming that i will have until 20.12.2018 to pay for my purchase, so that I avoid any interest charged. However this was not the case, 08.12.2018 I was charged interest of R396.15!!! I called the call centre and spoke to Patrick Chiziane, he was very confused, not helpful, sent me my statement via email and put me on hold for 15min!!! I cut the call as I was tired of waiting. I proceeded to email my private banker Preshnie Shunmugam at the Amanzimtoti branch. Its been 2 days and she has not come back to me. To add insult to injury 10.12.2018 I was charged R25.22 for my statement which was emailed to me by Patrick. I was not even informed that there was a charge attached to receiving my statement via email!!! I am absolutely livid! The service i received was absolutely shocking. If those charges are not reversed. i will simply walk into Standard Bank this Saturday, close my 3 accounts and take my Christmas spending elsewhere. There are a plethora of banks out there.