Double charge on hardware again

I refer to the following reference number provided by your call centre: ***<br> <br> I notfied you in October that you had charged me double for Hardware (H/W)<br> <br> In a second call to the contact centre a week after notifying you of the error the operator confirmed that the fee has been reversed. Low and behold debit order ran off and the h/w fee was still processed.<br> <br> November the h/w was correct. December it is wrong again.<br> <br> Please revert and refund me the hardware fee owing.<br>