Appalling service from Old Mutual

I recently changed banks in January , I advised my new bank about all the companies that I have debit orders with , all debit orders switching was successful and I received confirmation of this from my bank .

Funny enough my Old mutual debit orders didnt go through , I have a life cover and Funeral policy , the following month the group scheme debit order went through without me contacting them which means the details were indeed received

I then received a call from Moegamad Taahir January who advised that my policy has been cancelled I asked how becuase I submitted the new banking details , he confirmed that my new banking details were correct , he requested that I send a letter requesting my policy to be reinstated and I did that and advised on the letter that they can debit me for all the missed payments due to the mishaps ....this was on the 19th of March , till this day no response from him ....I followed up again on the 06th still no feedback .......is it fair for old mutual to terminate life policies after one missed payment and after they confirmed that they have updated my banking details to the new banking details but they never debited ?