Headlight Switch problems of the 2005 Kia Motor Optima

Both low beam headlights blow out simultaneously. When this happened, high beams (separate bulbs and switch) would only work sporadically (switched 'on', nothing. Switched again, may come 'on', turned 'off' then 'on' may or may not come on). Dealer states 'it happens, they burn out', yet said the battery needed to be replaced. (?) non warranty, so you pay. Another complaint on the same car year/make/model, same issue, has already been filed with you. In addition, 'google' search shows many entries for this same problem on kia and Hyundai vehicles (same manufacturer) over many models/years. Signs point to possible defective charging of battery by vehicle's electrical system (maybe why they replaced the battery at the same time). Battery was previously fine. I've had many electrical problems with the car, things stop working, then work on their own (power window won't work, sticks part open. Switch does nothing. Then suddenly later window lowers/raises without switch being touched. Trunk suddenly pops open). Definite electrical problem on these make of vehicles over many years which neither manufacturer is going to address themselves. Unless you do something, many will be paying for service caused by their negligence. . Also, seat belt does not retract all the time. My vehicle was purchased new.