Lufthansa charging again for the cancelled air tickets

Be careful buying air tickets from Lufthansa. I bought economy prime tickets to Warsaw on the 6 November 2019 and cancelled them because of availability of place for my dogs in cargo hold the same day. I received cancellation notice the same day with a note about full refund. Contacted the bank next day - the charge was reversed. To my utter surprise Lufthansa charged for those tickets again on the 9 November 2019 although on their site the tickets are cancelled. To the their satisfaction one can only contact them via email - the credit card warned me that airlines like to do that. I had never expected that after German airline but after the diesel gate looks like everything is possible.