Is it legal to refuse to pay employees? England

To clarify, I (19M) actually only worked there for a week before I quit for unfair working conditions, and because they generally seem a bit sketchy.

First, they hired me literally the same day as my interview, and gave me about 15 minutes of “training” before shoving me on the phones.

The salary was literally only £650 a month, equating to about £5, maybe £6 an hour, plus commission. Unpaid breaks, unpaid sick leave, and they didn’t pay tax, as far as I’m aware.

They said that they won’t pay until we’ve worked there for 30 days. So, I understand that they won’t pay me, considering it was just a week.

But my partner (21M) has just been fired 3 days before they’re due to pay him, so he’s worked there for about 27 days. We worked at the same job. They fired him due to poor attendance, but that was due to several doctor’s appointments, and violent migraines. They’re now “unsure on whether they’re going to pay him”.

I’m not the only one to quit after only being there for a few days. Three other coworkers of ours also quit due to the stress we all suffered at work. Not to mention the mould problem our employers refused to look into.

This can’t legal, can it?

Edit for anyone interested, I just found out that we don’t even get a payslip when we’re payed. Our friend/coworker got paid, and she said there’s no payslip at all. Just sent the money over to her account.