O2

I haven't had any signal for 2days my son my husband all 02 have signal iv tried turning my phone off and on still no good why

I have been experiencing signal problems we have 4 phones at this address all 02 network and none of us can get a signal this happened ladt month as well and was of for 4 days we were told a madt wss down and has now been repaired but still no signal...