No service

I have a Vodacom Cellphone contract. Every time we are having loadshedding (as it happens daily now), I cannot use my phone. I get a 'NO SERVICE' notification. I phoned customer services last night and was told it's not their fault? Now whose fault is it? I visited a Vodacom shop this morning and was told it just happens? No one can tell you why and whose problem it is. As a paying client that has been with them for many years, and I never experienced this before. Can we get ligit answers please.