Disproportionate Charges for use of second licence in error

My colleague has a single quarterly licence which she pays £300 per quarter to use Microstation as part of her architectural design firm.

She has been charged an extra £1000 this quarter due to activating a second licence for ten minutes back in mid January.  

This activation was due to the purchase of new hardware in the form of a desktop and laptop which she was installing the software on both. It woudl appear in doing so she inadvertently utilised a second licence. 

She is not consistently using a second licence or has any other staff which do so. Her annual usage statistics would show that this is a one off and therefore potentially a mistake or error but the accounts conveniently ignore this and bill her anyway. 

In speaking with her account manager she was fobbed off, told they couldn't help her and redirected to the Bentleky website. We will be pursuing this further with Bentley about this wholly appalling level of service.

She pays annually £1200 to use Microstation and is a sole practitioner. A Thousand pounds for Ten Minutes use is complete extortion and I fail to understand how it is justified. If she was consistently using a second licence then she would need to pay for it and usage stats would prove that - but this was clearly not the case.

Does anyone have any experience of this? What can be done?