Real worse service

I have a case to separate my accounts, which when I first called the turnaround time was 72 hours and stayed more than a week and my case was not resolved. I called three times and the answer is your case is still under investigation(i don't know what they are investigating because I just want my accounts separated (which are up to date by payments). The lady i spoke to on the last call change the turnaround time now is 7 working days. my case was open on 14/06/21 and now is 28/06/21 it has not to be resolved. The responses from the call centre are really not helpful eg "I will escalate it to the back office and send it to my manager". If I say can I speak to the back office or manager, response "there are no numbers for back office and the manager is contacted by email due to covid".

Hope they can remove the call centre, useless middle man and customers can call the back office. I really don't understand what is so hard to separate my accounts.