Physically impossible to cancel life insurance

I have now sent the same e-mail to 5 different Ooba e-mail addresses, including the Complaints department and I have not heard a word from a single person at this company. I asked for confirmation of receipt of my cancellation letter numerous times, but it seems no one at this company reads e-mails. I expect this to be resolved ASAP, I refuse to pay for 2 life insurance policies purely because it is physically impossible to cancel an Ooba life insurance policy.