Did your insurer sort out the courtesy car for you?
What I'm getting at here is that if you signed up for it yourself using an AMC, then technically you're on the hook for the hire cost which I imagine is not going to be cheap. Insurance is about mitigating losses, and whilst having that on hire for a couple of weeks probably isn't going to cause anyone to bat an eyelid and the expense will no doubt be paid by the TP insurer, if it carries on any longer then you're going to want to swap that for something significantly cheaper to hire. Otherwise you run the very real risk of being on the hook for the bill.
Of course, ignore all that if your insurer is supplying and you've not signed the usual agreement that AMCs make you sign.