Credit Card not working - Client blamed

My new Business Credit Card can not make any online payments. We have tried to use it over three different online shops and over three different computers, with no luck and the same error message (to contact FNB). I called FNB and from their side they say the card is fine and that nothing is wrong, they said it must be the site I am trying to buy on, so according to them Woolworths and The Courier Guys Xpress online sites are not working. I said I would then like another credit card as this one is not working, but I will not be paying for any charges for the credit card. FNB then said no as it is on my side that the card is not working. Now I have to go into my branch and show them the card is not working. It will take 3 hours of my precious work time to do this, after being on the phone for an hour trying to sort out the problem. Which apparently according to them does not exist. If they do not value my business banking is it time to move banks?