False advertising. Dont honor their prices shown

Yesterday whilst trying to book tickets for myself and my family for a holiday next year, I was shocked to learn that they dont honor their prices shown. Upon trying to pay the ticket and do the reservations, the price had sky rocketed to nearly double the price on the payment page, I contact the call centre, not recieving a warm welcome, which in turn said I need to pay the price given. I inturn explained that the price advertised, had nearly doubled when trying to make a payment. I have taken snapshots from begining of booking to the very end which shows the price changing at the end. I am a avid supporter of Lufthansa and never in my years did I think I would be treated in such a manner, this is false advertising at its best and now they refusing to honor the price advertised in the beginning.