Poor customer service and unauthorised debit order

Retirement investment was paid up and request was made to pay the funds over in a "better" retirement investment. I was supposes to get a bonus for this new policy but due the penalty that I pay for the transfer of the 1st policy that "bonus" comes down to basically nothing, I did enquiry about this and no response was received. Now they deducted premiums for both policies from my bank account where I only gave permission for one premium to be deducted. In order to rectify this I have to visit my bank, get the debit order reversed, which I pay for, and then a new debit order will be deducted, which I also pay for!!! No matter what, the customer always pay for their mistakes. My question: why can't they pay back the money which they deducted incorrectly?