Client Terminating My Contract Early With No Valid Reason

[fidot]

Get A Written Reference

My advice would be, once you had been told that you hadn't done anything wrong, to say "great, would you mind supplying a written reference then". The main purpose of that approach is obtaining the reference for using in getting the next gig (which should be your only concern). However, in this case, it has the secondary effect of giving the OP closure too.

[suespence]

I know as a contractor if the client decides to get rid of you early then that's their prerogative but, all the same, is it normal and common for them to do this with no real justification?

It might not always be common, but I do consider that 'normal' for contracting. It feels like a rejection, but it's just business. Even FTE is not immune to such things.