I have Quit my job but I haven't been paid my last hours I worked

[Jaker118]

I have looked this up online a little bit but all of the forums are in the situation of employment. I worked at this place for about 7 months. For the first 5 months I was only doing 1 day a week and he payed me cash as it's part time work. But then for the last 2 months I increased my hours but it was still part time but due to there being so many hours we did monthly payments. It was at this point my boss said that I should register as self employed due to the amount of hours and the fact I wasn't employed by him before, but I forgot to do this as I was only did the increase hours for a total of about 5/6 weeks. The first month went by and it was fine but then half way through the second month I quit the job but I had works 15 hours. So I messaged my boss and he said that he would pay me once the month is over but my pay day is now a week late and I have been texting him nearly everyday since pay day and he isn't replying to me and I can see that some of the messages he had read them but just chose to ignore. What situation does this put me in as I have bills to pay and I have no money to pay them but I don't know what I can do because I wasn't employed by him.