Someone just tried to take your money!! Of course it can be re-programmed. If yiu had to buy a new phone system everytime you lost programming, I think people would have stuck with the oldie but goodie 1A2 systems circa the 1960's/70's.
Try this website :https://www.wedophones.com/SamsungManualsLead.htm.
It doesn't have your EXACT system listed, but the other Prostar manual may work for you. Also try
https://www.p1bc.com. They have lots of manuals also.