Duplicate payment

I bought silicone for bathroom and new plug but my Nefbank American Express was decline no valid reason on slip. I know there are sufficient funds as i got paid yesterday and use card this morning at another shop no problem. I gave them another card but also declined. I told her it must be machine as there are money in card so they brought her a cordless machine and it show approved just to discover a problem with orinting the transaction. Manager Venessa tried like 4 times to reprint but it refused. After 20 minutes struggle with a manager that is so unfriendly not apologising frim Checkers side that their machines foes not work i gave her my pretorium trust card so made double payment and left shop i was in car when a supervisor rush to my car to stop me and i went back with my stuff i bought. They wanted to reverse money on my card but i did pay with cheque. The gave me cash back. Was a very bad customer service ever and i felt horrible that my card was declined and every just look at you. Will mot go back to this store for a long time never felt so horrible in year with the assistence i got and still no apology only blaming the card machine. Very bad service