Product: Credit card or prepaid card

I tried to schedule a payment through my Capital One banking phone app for {$1600.00} which was the full balance owed as of XX/XX/2020 on my Capital One Quicksilver credit card ; I received an error message indicating the payment didnt go through, but received an email that it did. I tried to schedule the payment again through my phone app, but received an alert stating a payment for that amount has already been scheduled. I went back to my credit card details in the phone app, and it didnt show a pending payment, so I called customer service and the rep confirmed there is a payment scheduled. I further inquired whether this is going to be an issue and advised my credit card account through the phone app doesnt show a pending payment ; rep assured me the payment is schedule and provided confirmation code : XXXX. 

I tried to use my Capital One Quicksilver credit card today, XX/XX/2020 and my card was declined. I called customer service and asked to speak with a supervisor, but the representative instead transferred me to a fraud specialist. The fraud specialist transferred me to her supervisor who only identified herself as XXXX. I expressed my frustration and advised I didnt understand why this was taking so long to clear as the account I used to draft the payment for this credit card is with the same financial institution as this credit card, and that I like to use this credit card account because I receive cash back. XXXX  stated she could call the banking department to verify the funds are available ; a call was conferenced with the banking department and the representative stated the payment hadnt drafted from my account, but confirmed I had more than enough funds for the payment to clear. XXXX  still refused to release the line of credit. I asked to speak with her superior,  XXXX  stated I had reached the highest level of escalation. I stated thats ridiculous that I should be able to speak with someone higher than her if I request it, and asked if she could email a superior to call me back. XXXX  refused stated her superior is only there for administrative purposes, and they do not take call escalations. I asked how Im supposed to file a complaint, and XXXX  stated she will file a complaint on herself. I stated thats ridiculous because I have no way of knowing if shes going to put in the right information regarding my complaint. XXXX  stated the only other way I could file a complaint would be to go to Capital Ones website. I asked for her full first name, XXXX  refused to provide me with her full first name and insisted she only goes by XXXX. I asked how else Im supposed to identify her, she provided me with her employee ID # XXXX. I went to Capital Ones website, and there was no information in regards to filing a complaint. I called customer service again, spoke with a representative named XXXX and advised I was calling to file a complaint ; he asked to place me on hold while he researched some information, then blind transferred me to a supervisor named XXXX. XXXX took my complaint and advised XXXX  shouldve transferred me to customer relations as that it where complaints and escalations are supposed to be sent, and that she is required to provide her full first name if a customer requests it. 

After all of this, even though the representative in banking confirmed I had more than enough funds for the credit card payment to draft from an account thats with THE SAME financial institution, they still refused to release the line of credit to me and stated I would have to wait 7 calendar days from when the payment was processed. Now I am being denied cash back rewards on the purchase I made today, as well as any further purchases Im going to make during this 7-day period. Im starting to believe that this is a ploy so that Capital One can limit the amount of cash back rewards Im receiving. Just as a reference, I have a Capital One Platinum credit card account that is NOT a rewards credit card, and I processed a full balance payment of {$230.00} to draft from my XXXX XXXX XXXX  checking account ; no only has that payment already posted to that credit card, the credit limit is available for me to use today. The only difference is the one taking longer for the credit line to be released is a rewards card, and the one with the credit limit immediately available is not. Unfair practices and ridiculous to say the least.