I can tell you that up till a year ago the answer was NO. I don't know since then as I am out of the business. They have good reason to say No....
.... They dont' know how many trips you've been on since insurance date commenced. The cost of three individual weekly policies is often close to that of an an annual policy. So, theoretically, if your policy started 1st August you could have popped in and out of Ireland a few times -so you couldn't then turn round and say we want a proportion of the twelve months policy back.