Product: Credit card

I have had Barclaycard since XXXX. I enjoy using the card and convince checks and manage my financial very wisely. I have wrote many checks using Barclaycard and my account went from XXXX credit line to {$12000.00}. Recently, I wrote a check for {$6000.00} at 2 % fees. The next day XXXX/XXXX/XXXX, I called Barclaycard XXXX XXXX XXXX XXXX XXXX to cancel the check. After a few minutes conversation with customer service rep. She said she can not see the check but she will cancel it and put a stop to it. On XXXX XXXX, XXXX I saw the check posted to my account and called again customer service to inquire about why my account had been debited {$6000.00} plus fees. Customer service rep. XXXX created a case # XXXX and stated that she noticed as well that I called XXXX XXXX, XXXX to cancel the check, she stated the check is canceled and she will see to it. NOTE, XXXX knew this was convenience check and stated in the benign of out phone call conversation that this was a convenience check. Now everyone is saying OH, we do n't cancel convenience checks. But no one told me this on my XXXX call they can not cancel the check. in fact the first XXXX calls to customer service give the impression that i was in a good hands and i should not be worried. When I realized that check was still posted to my account, I call again XXXX XXXX XXXX and spoke a customer service rep ( XXXX XXXX who stated confidently that the check is indeed canceled and I should not worry about it at all. I asked why is it still posted to my account and He said it takes several days to clear and I should not worry.. 
XXXX XXXX, XXXX I got a text message from the person I wrote the check to saying in a text message " Thank you '', I said for what and he said " the check cleared ''. I immediately called customer service to find out why the check is cleared and who is responsible for it? Their answer was they can not stop convenience check!!! I did not know what to do. this is a big check and I can not assume the responsibility when I was told incorrect information by XXXX customer service reps. on XXXX separate times. 
XXXX/XXXX/XXXX called to cancel the check exhibit 1 recorded conversation. 
XXXX/XXXX/XXXX called to again to confirm the check was canceled. Exhibit XXXX recorded conversationXX/XX/XXXX called the third to enquire why my account is debited with XXXX at this point I was assured that the check was canceled and I need not to worry, it just takes couple days to clear from my account. Exhibit XXXX recorded conversation. 
XXXX/XXXX/XXXX called customer service to ask why the check clears after it was canceled? 
Customer service stated they can not cancel convent checks. I said that is not what I was told on XXXX separate calls, in fact I was so sure that the check is canceled when I called on XXXX/XXXX/XXXX. 
XXXX/XXXX/XXXX called again and no one wanted or know how to help me. So they suggest to talk to dispute department which was located in XXXX, XXXX. The customer service dispute Rep was located in XXXX, XXXX did not know what do. This dispute was just to get rid of me. ( Exhibit 4 ) recorded conversationBarclaycard customer service misinformed me on three separate times and are now avoiding solving my issue. I have offered to work with them. I am very confused and do not know what do. I need your helpThank you, XXXX XXXXExhibits are the phone recorded conversation between me and XXXX Customer Service Rep.