I loved them... until they stopped working

I ordered five sets of these lights and strung them all up in my classroom to create a soothing mood for reading time. I loved the way they looked and how they made my classroom have a calm feeling. My students loved them, too - they asked me to turn our normal classroom lights off and turn these string lights on every day. They were beautiful and so awesome ... until one of the strings suddenly stopped working. I tried to problem solve and figured out that the lights would light up again if I changed the white remote receiver that is in between the lights and the power plug. Two weeks later, another string of lights did the same thing. Unfortunately I don't have extras of these white remote receivers, so my room is only partially lit up now. I would love to get all five sets working again. Is there any way to get some replacements for the white remote receivers or can I buy them somewhere?

###

