voucher pins not accepted by meter

My 18 month old twins n their 6 month old baby sister, dad n I have just spent the entire night in the cold n dark because the Unipin meter would not accept any of our electricity 9voucher numbers. My husband bought 2 vouchers thinking that there could be a problem with the 1. I then bought a voucher via Internet banking n still the same..... NOTHING! This is not the first time this has happened but now we're in the middle of a cold front. We would love to go back to the old system but unfortunately we were told that we can't. Should anyone in my family get sick, who will foot the hospital n medicine bills?