Old Mutual refuse to terminate Life Cover policy.

I have had a Life Insurance policy with OLD MUTUAL since 2002. In December 2023 I was advised of a 25% premium increase. I decided I can no longer afford the policy and called OM on 19 December to cancel the policy wef 31 December 2023. The lady who answered said my cancellation has to be in writing. On 20 December I submitted the written cancellation which was acknowledged by email. On 02 January 2024 OM debited the new premium. I called to advise my displeasure to find they only actioned the cancellation request on 04/01/24. They then granted themselves a Feb '24 and Mar '24 premium deduction from my bank account. That is both a disrespect for their client, and a violation of a direct written and acknowledged instruction. Is there an ombud I can ask to intervene?