Ridiculous service!

My mom had a policy with Platinum life that I cancelled. They assured me that they won't debit from her account since the policy is cancelled. They first called constantly asking to reinstate the policy. Then they called and said she's behind on the policy. Which was cancelled months ago. Yesterday they debited her account for a policy that she doesn't have. Can you tell me how you can do something like that? She's a pensioner! That's the only income she has. They took her last money.