Promise of good service but not delivered .

In December 2022 there was ***** on my credit card. About 3 weeks ago the bank called me to tell me that the bank were refunding me and this would take a few days. This did not happen. I called the bank and they were surprised that the refund had not been done, as was authorised. There was a high call volume on the phone to the bank. I used the secure chat function on the app. I was number 6 in the queue. I typed what the issue was and was transferred to the ***** section. I was number 2 in the queue and repeated my issue. After a total of 30 minutes there was no reply. I later got an apology that the system was not responding. At 10:07 on Monday 6 Feb a started a new chat. I repeated the whole saga and responded to the texts. At 10:41 I got a message that " we have had no further responds" and the bank ended the chat . I can't resolve this by phoning the bank or by secure chat.