Cold air returns are in the ceiling and cold air is coming down into the house from the attic through the cold air returns. I have 3 return airs on the one side of the house one in each bedroom and on in the hallway. This side of the house is at least 10 degrees colder and the furnace runs longs since the thermastat is in the hallway between the two bedrooms. Is there a product that can stop the cold air from coming down into the house or what do you think is my best option?

Make sure the return air ducts are insulated and properly sealed at the penetration of the ceiling so no cold attic air can enter the room. Where is the furnace located? Attic? Roof top?

Furnace is in the attic.

With the furnace in the attic there is not much you can do that would be reasonable in price except to try and divert the cold air returns to an area that would not be as noticeable. In other words an area that you would not feel the cold air.

The problem is that the attic is cold and the cold migrates from the attic down into the living space. If the ducts are sealed properly etc that is all that really can be done except to try to move the return airs to a different location where it will not bother you. Without being able to see your complete exact circumstance it also makes it more difficult. You might contact a HVAC company in your area as see if they can shed more light on the problem.

How many cold air returns do you have?

One in each bedroom and one main one in the hallway so 3 on that side of the house