I hope they have demanded prepayment because, in the case of NRW...

I hope they have demanded prepayment because, in the case of NRW the lawyers were the best and they took Samsung to Supreme Court.
Samsung told to pay -
Samsung appeals
Appeal court also orders Samsung to pay what it owes.
Samsung refuses and says something along the lines of “Well we are an international company so we have the right to appeal,again and this will cost you years and a mint because we are taking to International Court in Singapore this time ..
Sn NRW walks away from something like $60 million or more which is owed to it and settles for the $30 million which Samsung offers.

If you do a bit of research you’ll find this kind of behaviour is frequently reported.
NRW learned the lesson to be really wary of international operators ....and yes -payment up front or getting them to supply all equip,eat or whatever is probably best way to go .
Business world full of bad debtors along with Management decisions on how to cope with them.
Cheers