Citibank Credit Card Complaint

Citibank Credit card department,

Transaction issue Florida

I placed an online order on Home Depot.com for a washer and dryer using my Home Depot credit card ( issued by Citibank ). My account at the time had a $0.00 balance with just under $6900.00 limit. Once I placed the orders, i received emails advising that the charges were declined. When I contacted Citibank, they advised that the charges were approved. When I then contacted Home Depot, they advised that the charge was declined. Neither Home Depot or Citibank have been able to advise me why the charges were declined and as a consumer, I have a right to know why the decline