Poor service

I have been charged R150 #ITEM PAID NO FUNDS 1 ITEMS ON 21/05/1 ITEMS ON 21/05/03 I never purchased anything on that date FNB refuses to assist telling me they let the transaction through even though i didn't have money but the sms I received from fnb after my purchase states otherwise, I logged a complaint ***F I got a reply which has got nothing to do with my query I called in and spoke to Pamela who was just like a well programmed robot