On the STB and in my phone if I view my account details in the MyJio app, it displays the base plan and any active voucher details separately, i.e. how much data left for each. So if I haven't exhausted my base plan's monthly data yet, depending on the extra data voucher activated it displays full 200 GB left of 200 GB, or 50 GB left of 50 GB as the case may be. I have had multiple vouchers activated and in queue, waiting to be used, and all have shown up properly (till now).