We have a king-size dual-control blanket. One

We have a king-size dual-control blanket. One control is working and heating half the blanket. The other control just blinks and cannot be shut off or create heat on the other half of the blanket. The blanket worked o.k. for about six months - should I be able to expect a longer life? Can the one control be fixed or can I buy just a set of controls without having to buy a whole blanket.