Lack of communtion and no follow up

On 2020-08-13 I visited Edgars branch Zevenwaght to submit a claim of my late mother, Edgars markets the policy as a joint venture with hollard life. I completed the paper work with supporting documents and the cashier assured me that documents will be forwarded to Hollard. On 2020-08-14 I received an email stating that they are unable to continue processing the claim as the following documents are outstanding: claimant details to submit, with reference ***9, i tried contacting them Iines were busy, kept on phoning with close to an hour on the phone to no success of being assisted, on 2020-08-14 @ 22:56 I sent an email and I received an automated responce saying they will get back to me in two working days or else I should call them, I tried calling to no success, on 2020-08-17 I visited Zevenwaght Edgars to raise my concern and to rectify problem, they could not find my documents and they did not come back to me as promised, on 2020-08-19 I visited Hollard at Delft mall, they could not assist me I was told to sit and they will call, I sat and no positive outcome phones kept on ringing, On 2020-08-20 I tried contacting Hollard again no success. How can this matter be resolved I have tried all avenues.