Vuamtel is the worst ever

Vumatel is the worst. Yesterday a vumatel van came now bare in mind my internet was fine no issues I did not log any calls as I had no problems. They came with no warning,not saying why they here and they were busy in that little black box outside the property. By the time they left my internet was down. I logged a call which took me hole day and they telling me I have a fibre fault on my line. How? Before they worked here nothing was wrong and now they can't even tell me when they will be fixing this problem.