What are legal ramifications of non-payment of credit cards in the
state.of South Carolina if you do not want to file bankruptcy, just stop payment?

The credit card could geta lien against any assets you own. (via a
court proceeding).  They can also forceyouinto bankruptcy. See
"Involuntary bankruptcy"

You can contest the charge (there are time limits, and you must notify
in writing), that can DELAY having to pay, but ultimately, you are
responsible for the debt --if you received/accepted a product or
service.