Can I claim Contructive Unfair Dismissal?

I work as a delivery driver for a very small company

I complained when my wages were short after taking a couple of days holiday and got told that it was because they had to pay someone else to do my rounds!

I was given my holiday pay begrugdingly later that day.

The next day when I went into work I was told not to go in early at the weekend.

The day after that I was told one of my rounds was to be taken off me.

3 days after my first round was taken off me I was given a weeks notice that another round was to be taken off me. I also had the amount that I was paid for doing Sunday work reduced without any consultation.

The fact of the matter is that a weeks wage was reduced by just under 64%!

My work was reduced supposingly due to cost cutting.  However, existing employees of the company have been given my work.

I walked out on Christmas Eve.

Does it matter that I don't have a written contract but have been employeyed there over 6 years and have been doing the same rounds for 4 or 5 years?

Thank you in advance