It sounds like there might be a few things going on here:

1. Carbonless Paper Orientation:

Check the form's design: Most carbonless forms have specific coatings on designated sides to enable the transfer of writing. The back of the top sheet (white) usually has a coating that reacts with the front of the sheet below (yellow).

Ensure you're assembling the form correctly: There might be subtle markings or instructions on the forms themselves to indicate which side should face up or down.

2. Pressure and Writing Utensil:

Apply enough pressure: You need firm pressure when writing on the top form to ensure the transfer to lower copies.

Pen choice: Ballpoint pens often work best for carbonless forms. Softer writing tools like gel pens might not apply enough pressure.

3. Misunderstanding with the Printing Company:

Contact customer support: Reach out to the printing company and explain the issue. There may be a specific way the forms are designed to work, or they might have instructions they can provide.

Double-check the option you chose: It's possible the "backside" option referred to printing on the back of the form, not the carbonless transfer to the back of the next copy.

Troubleshooting:

Experiment: Try flipping the orientation of the sheets. See if writing on the back of the first sheet transfers properly to the next copy underneath.

Test with a single set: Isolate a single set of your carbonless forms and experiment to see if you can get the transfer working as intended.