My boss won’t sign my employers letter for job seekers.

I work in a shop for two years I have no contract, nothing but recently for the past few weeks and a few weeks in between before this I have received zero hours of work. Recently I had decided to attempt to receive welfare benefits about two weeks ago I’ve filled out all paperwork necessary but the employer’s letter. I go into my place of work and my boss isn’t in so I hand it to one of the mangers and he rings in asking if he can sign the papers or send it off to whomever needs to fill them. I leave and return after the weekend seeing as my boss doesn’t work the weekends. As it turns out two or three weeks prior I had missed a day of work I wasn’t aware of. My mistake I apologise profusely to everyone that would listen and this was the first time something like this ever happened. Once I go into my bosses office he says “I didn’t have time, nor do I think I should be wasting my time signing papers for someone who doesn’t show up.” I apologise profusely again but he says he’ll have it signed later that week. I return later that week with no form more attitude and him saying he’ll send it to someone and I’ll receive an email. It’s been over a week and no email, what do I do?