Our child''s grandparents have taken custody behind our backs, while my husband was serving in Korea. They are now denying contact despite court order

My son, age 6, was staying with his father''s parents while he was deployed (air force) to Korea. While he was gone, they initiated custody changes without notifying either of us. I got the notice of the hearing to finalize this change a few days before my husband returned. It was set for the day after I received the notice, and since it was in Virginia and I was in Iowa, there was no way for me to get there by the time mentioned. The custody hearing was postponed, thanks to a communication from my husband''s first Sargent. We made it there together. His parents, in the hearing, strung together a line of outright lies and half-truths, and managed to convince the judge to give them custody of our son. They did this without a shred of actual evidence against either of us, and we can disprove most of what they have said by assembling documents from his past and getting statements from people involved. Unfortunately, we do not have the funds available to get a lawyer.