<<Disclaimer:  Verify this information before applying it to your situation.>>

800 numbers for reaching consumer departments of cereal
companies:

Post cereals:
1-800-431-POST  8 a.m. to 6 p.m.

General Mills:
1-800-328-1144  7:30 a.m. to 5:30 p.m. CST

Ralston Purina:
1-800-345-5678  9 a.m. to 4 p.m. CST
Kellog:
1-800-962-1412  8 a.m. to 8 p.m. EST

We use these numbers to call and lobby for them to try and
provide more cereals that are GF.

Melody in NH