Yesterday I went to Jubilee mall brunch in, friendly officials assisted me, however they told me that they could not see or ditect any fault with my old card, but when I tried to use it it was not working

Yesterday I went to Jubilee mall brunch in, friendly officials assisted me, however they told me that they could not see or ditect any fault with my old card, but when I tried to use it it was not working. At the end they replaced my card and promised I will not be charged for the replacement. Today when I logging into my account. They charged me. The sad part about the old card I didn't even use it for more than 5 months. So what will happen if this new 1 will do the same? I am not happy