Appalling service in paying out death claim

My mother passed away on the 14th June 2021. I have 2 policies with Metropolitan, policy number *** and ***. I called Metropolitan on the 15th June to put in the claim. I took photos of the required documentation (my ID, bank statement, death certificate and notification of death) and emailed these to *** - in the subject line I used both my policy numbers. I was informed over the phone that it was would take 48 hrs to process the claims. I called Metropolitan on Friday 18th June to find out how far the claim was, I was informed that my mother's ID was outstanding. I had not been asked to provide her ID in the 1st telephone conversation. My mother was buried on the 20th of June without any of my claims paid out. Policy number *** paid out on 23rd June, 3 days after the funeral! I called Metropolitan asking why they had not paid the other policy, to which they responded that they hadn't received my mother's ID. So how did they pay out the other policy? The consultant apologized and promised to escalate my issue and have it resolved within 48 hrs. Today marks 13 days since I've been waiting on Metropolitan to pay out my claims. I find this service totally appalling and unacceptable!