Acting in bad faith

I have been having a policy with Old Mutual for the past 15 years.I recently skipped premiums by debit order as I changed banks, but made cash payments to make up for the shortfall.In November I arranged with Old mutual to deduct the outstanding amount from the new account only to discover that the debit order was not processed.When I called to enquire I was then told that the policy has been cancelled even after I was advised by email that the policy was reinstated .I think Old Mutual acted on bad faith.