Markham battle to close account

I opened an account with Markham many years ago. The account the became obsolete and I requested for it to be closed. This has been ongoing since 2017 , an undertaking was given in writing that the account would be closed by 12/12/20, then another undertaking for 12/06/21, then 12/7/2021. Today after a lot of correspondence , I have lodged a formal complaint with the credit ombudsman . Markham is just ignoring my wish to close this account, is in incompetence or maliciousness.