Old mutual refuses to refund my premium.

My life cover lapsed on 13 August 2021,hence I made a direct cash deposit as payment on 17th August into the company's nedbank account unaware about the policy's status. Few days later after I learned that the policy lapsed before payment I sent copy of deposit slip and a request for a refund but still today the company does not want to refund me. I have contacted them many times and resent the request with attached receipt to various email addresses as requested but still no response.