Hello and sorry you're having problems. The original remote control for your Yamaha can be purchased at the link below:
Also, any other model Yamaha remote will work for basic functions as well- as they have the same code set.
Universal remotes that support an "AV" or "Audio device" will also have codes for Yamaha and will control basic functions like volume and power.
Feel free to reply back if you need more help, or want to reply back with more details. It does not cost you anything more to reply back once you've rated. Please do rate me positively (at least 3 STARS) and I will continue with you until this is sorted. The positive rating ensures I am credited for my work.