Technically, according to the terms and conditions you signed up to you would not be entitled to a refund.
That said, if you get a sympathetic agent the may make an ex gracia payment based on the days you are without. So you will have to wait until the problem is fixed before claiming
If you have problems with calls at home then you need to use WiFi Calling which will allow you to make and receive calls without a signal
https://www.o2.co.uk/connectivity/wifi-and-4g-calling
This is not O2 and we are all customers here similar to yourself and cannot answer account type queries.
