Check for 3rd party credit checking companies. I had similar issues. I was referred to my bank when transaction delined. Contacted bank, no problem with the card. Nothing at all on screen showing any issue, card or otherwise. Took screen shot of transaction decline. In small print top of screen shot noticed "wind cave", did research. Found they are a credit checking mob. Contacted them. Didn't want to know about the issue. Contacted the merchant, trader. Informed them I would be taking my business elsewhere. They requested I try transaction againin a few minutes. Bingo, transaction accepted. Not sure of the background to windcave & merchant relationship but appears the merchant can, will, in these instances overridre delined transaction. Hope this might assist.