Refund claim

Sanlam Sky is the worst insurance company I have ever had. I sent them a paid up letter in April to cancel the investment. Two months later they were still deducting for the policy,when i contacted them they claimed not to have received my cancellation letter. I then submitted all the evidence regarding the enquiry I made in April. The matter was referred to investigation, I was then told my policy does not have a refund regardless of the evidence I submitted. Their communication is very poor,now they want to refund only one premium while they took my money for two months after cancellation.