Old Mutual promise to pay never happened.

I am a client of Old Mutual for more than 35 years. The end of April 2021 I signed documents for two policies to be paid out and one was paid out soon after but a bigger one never paid out. Old Mutual promised to pay and that everything was in order but I never received payment. They then argued that they have done payment on the policy in question but did not reflect in my account up to date. I've now been ignored by them and it seems that they keep my many years of monthly payments to themselves.