Adding a huge interest amount for 3 days

I have an account with Foschini and paid 3 days late as I was busy with my mom's passing which was in Durban and I am based in Johannesburg. They added interest of R154.90 for those 3 days which is totally ridiculous as well as R2.80 for an SMS. These guys are *******. Can't wait to close my account as this is the first time that I have done this and it was out of my control.