Cashier with bad attitude

I'm very upset at how the cashier treated me, I handed her my SASSA card to pay for groceries, inputed my password then she tells me there's insufficient funds. I explained to her that cannot be , and she insisted that it was. I asked her to run the card again which she seem reluctant to do, instead she decided to give me a lecture about using my SASSA card which by the way I have been using for more than a year to pay for my groceries. Other cashiers never gave me a problem, yet this lady who probably didn't even finish school has the cheek to treat me like I was eight years old. Also there was not one manager on the floor for me to complain too. The employees at this store don't know anything of customer service. I don't appreciate been treated like an idiot when I am supporting a business, even if I'm using my SASSA card it still money that I am giving your'll.