claims department giving me a runaround

My son had an account with Russells but he passed away on the 30th of April 23.On his account I was his next of kin.Im tired of these endless calls that the account is in arrears I went to Russells Attlyn to report his death but I was advised that the account was opened at Sosha plaza..On the 13th May I went to Sosha plaza to submit the relevant documents but I was advised that the his insurance didn't have a beneficiary but I didn't have a problem with that because all I ever wanted was for the account to be closed..To my surprise I was called by their claim department that they didn't receive the documents but the documents were submitted on Saturday.Now the claims department is calling me advised me to go to Sosha plaza to request for policy number while they're just one call away from that store..So now I have to do their job and all they do is ask me to do follow ups with Sosha plaza but how make it make sense..Account number for deceased is ***6