Hyundai i20 48v hybrid battery failure and months off the road

The car is used for Driving Instruction, so it is my main source of income. No car = no income. Hyundai don't care about this, or that pupils are having to take tests in cars they've not driven before, or my dwindling savings account as i prop up my daily "life".
All this is on account of the 48V battery failing during a lesson. Systems started to shut down while the pupil was driving culminating in failed power steering and a flat bed to the local Hyundia dealership in The Radleys, Birmingham (Motorpoint).
I'm surprised that these items are not held in stock, as a fellow driving instructor who has the same car, had the same problem and that was fixed in a matter of days. Yep, two i20's, both driving instructor cars, both in Birmingham, both with the same fault.
For the last three weeks i've been told that it's an unusual problem and certainly not common to the car, or manufacturer. I've been told the part was ordered, got stuck at customers and now is in an unknown location. I've been told that no compensation for loss of earnings, loss of sleep, loss of reputation or failed tests is available.
Funny, as a family we bought 3 Hyundai's on the same day (2 x i20 and 1 x Tucson). All three are up for renewal at the same time. Do Hyundai care....
So my question...Do i just have to accept that i cannot work while the item meanders it's way from wherever and that this is really just "one of those things" - an isolated incident, or, is there something else i can do to get back in the seat teaching.