So if you were at the checkout and the employee there shouted out across the store that they didn't think you were allowed to buy a particular item, in other words you were trying to get away with something you weren't allowed to have...
You'd be fine about that?
Because thats what this is.
The vouchers usually have restrictions on what you can buy with them, it varies between Local Authorites and stores - 20 ish years ago when I had some for decorating my council house that had been trashed (they were effectively bribing me to take it with extra vouchers, no one wanted it!), I got the same treatment from a loud judgemental bitch in B&Q.
First she yelled 'You can't buy ladders on a DSS Voucher can you Maureen?' across the store..
Then it was 'ERE SHE'S GOT MORE THAN ONE VOUCHER, IS THAT ALLOWED MAUREEN...' (I do not know if Maureen was the voucher expert or just the only other person there!)...
I had a covering letter that detailed the amount and items that were not usually allowed, which I showed her and she appeared to read, but she insisted on yelling it all at her mate three tills down anyway.
Her entire attitude was 'you're scum, you don't deserve to have these things, you're playing the system and up to no good'.
I did ask if she wanted to get the manager and I could show him my letter and she shut up and put my purchases through the till then, because she knew the manager would agree the covering letter did indeed allow me to buy what I wanted - she just wanted a shot at humiliating me.
This unfortunately isn't a one off, people using vouchers from council/housing association etc to buy decorating goods or items to replace those damaged by trades people have often been subjected to attempts at humiliation or just poor customer service as a direct consequence of using vouchers.