On 01/10/2017 1:10 PM, mike wrote:
....

I bought an item at home depot. It was broke, so I took it back
for a replacement. They wouldn't swap it. Had to return it for
credit and buy the new one again. But the credit card was declined
and locked. I had to go home and call the CC company to get it turned
back on. Seems you can't buy/return/buy the same item with your credit
card. If I'd been out of town and dependent on that card, I'd have
been screwed.

Something other than just a return must've triggered it or you've got an
exceedingly picky CC issuer. I return stuff all the time via CC and
never had any such issue (including on occasion the case you mentioned,
altho most times it's a swap or straight return).