What BML is trying to do is commendable. There is an acute shortage of foreign currency because the government has failed to restructure debt or reduce USD spending. BML needs foreign currency to meet customer demand. So BML is working to buy USD from the parallel market, as the government will also not float the MVR.
In short:
1. The government has no plan for debt restructuring.
2. The government cannot reduce USD spending, and
3. The government will not float the MVR.
So, to keep the bank solvent, BML needs to acquire foreign currency.