Ann: Trading Halt, page-348

The “General Security Agreement” (also known as a fixed and floating charge) over the business, incorporates the debtors of that company.

My best guess is that invoices raised are between the SB and BRTV, and not Big UN.
BRTV seems to be the working sales arm.

Proof of sorts are identified via BIG UN website where it states:

Big Un Limited’s core operations are conducted by the wholly owned entity, Big Review TV Limited whose focus is on providing disruptive video marketing services to small-medium enterprises.

This is why the GSA FCC have is against BRTV, not BIG UN.

If the SB's are invoiced from BRTV, the SB's become debtors of BRTV via the invoice.
BIG UN is not the cash cow, its BRTV.