Discover Credit Card Complaint

Discover Credit card department,

Closing/Cancelling account Texas

I applied for a Discover IT '' credit card. and was approved, I sent in documents to prove my address and social security number and was told verbally that I was approved for a $1000.00 credit line and my card would arrive in 7-10 day. so I wait a week and the card never shows neither does an decline notice. I checked back online after a two weeks for my application status only to get a message stating that I has been declined for the card and I would be getting a letter in 7-10 days. I 'm very confused as to why they would approved me then deny me for a credit card and why no denial letter was ever sent out. I sent them everything they asked for - but I never received any correspondence from them after I think these are bad business practices and I ca n't help but think that is slightly discriminatory. My credit history is perfect never missed a payment on anything. So I really would like answers as to why I was approved then denied for a small credit line with no explanation