I join old mutual policy 2014, then 2021 policy laspse because I changed my account then when I visited old mutual branch they took the old account number and send it while they suppose to take the current one

I join old mutual policy 2014, then 2021 policy laspse because I changed my account then when I visited old mutual branch they took the old account number and send it while they suppose to take the current one. And now they don't want to reinstate the policy since I was trust worthy since 2014.