No response when querying being debited twice

I was billed twice for bank charges on my savings account in November last year. Three visits to my branch, and two e-mails to their costing centre, have elicited only a one word e-mailed response - 'investigating'. <br> <br> Firstly, this response is unprofessional and discourteous. Secondly, I would still make allowances for this if they were, in fact, investigating, but nothing has been forthcoming, other than a 'ticket number' - [#ID: 705baecd-qh7E-7vKN-bU7R-NHck5bx9lZyU#]<br> <br> This is, to all iintents and purposes, theft. How else would one justify a query that one has failed to resolve for five months?