Charged for someone else's policy

I have had home contents insurance with Discovery for 2 years. I tried to take the simple step of changing the bank account payment details on the policy, and from there things went wrong.

It started with my mistake, in one email, one time, I slightly misquoted my policy number. Instead of checking that policy number against my name, my ID number or my email address to see if it was correct, they changed the payment details on someone else's account.

They then emailed me and him with all of my details and all of his, which must break data protection legislation. They then debited my account for his policy premium twice, one of which I still haven't been able to get refunded to me.

When I complained to Discovery, they told me they had never emailed both of us and never given my details to anyone else. When I sent a screenshot of the email, proving it had happened, they stopped replying.

For the past 3 weeks I have phoned regularly, been told they can't take my bank details off the other guy's policy until they have refunded me. Which was going to be done 3 weeks ago, then 2 weeks ago, now this week - but still my money is not refunded and his policy has my bank details on.

Today, I gave up trying to get the payment back and tried to cancel my policy. After 10 minutes on hold I gave up and emailed them, so I wait and see what happens. I am told they have removed my bank details from his account, but I have no guarantee that that's the case, and I'm concerned when the next payment date comes round I will be billed again.

Everytime I phone I get a new person who doesn't know what has happened, and gives me the same response, that it will be sorted. You feel a bit powerless in the face of the bureaucracy that promises to sort something but never does, and then just promises the same thing again.

I have life insurance with discovery and will also be cancelling this, as I have no faith that if I were ever need to claim from any of these policies, that I would be given the help I need.