Been in current job since April 2018.
No contract, no T&Cs, nothing in writing at all, not even an email.
Paid weekly, paid for eg week 1 at the end of week 2 (week lying on)
Just come back from 10 days holiday and my pay last week (which was all holiday pay) was much lower than usual.
When questioned, I was told I was actually due nothing, as I had not accrued the holiday I took. The money I had been paid was a favour, apparently 
I am now, waiting with bated breath to see if I get anything for my second holiday week.
Everything I have read says this is not correct and accrual is not allowed after the first year, and I have spoken to Acas who have confirmed this.
My boss is adament he is correct and is adament I am not entitled to anything. What to do?