Death claim not paid up 5 months now

Made a claim in August 2021 after a few days they said they are investigating even to this day i dont get any communication from them i always call them they have been giving the same answer that they are investigating, spoke with several agent n they have promised that their managers will give me a call back to answer me regarding whats taking so long on top of that they keep deducting the premium for the person that passed, i have went to their offices in Hatfield for answers n they said i must bring affidavit which i did bring in october 2021 but they still quiet n keep saying they are investing, so how long is one supposed to wait for you to pay me or worse conclude your investigation, im tired of calling your always for answers