Agreed. If anything goes down, talk to your first sergeant and even your legal council. I didn't go to my first sergeant because I felt that I could handle it myself. After being dicked around for a month, the guy that I sold my sound system to, he didn't pay up even though I let him use it until he could pay (which he claimed the end of the week). Well after the month ended, I told him we should go for a ride and just chill, which he accepted. I drove him to our legal office and said that if he did not pay me within the end of the week I am taking legal action and I would be seeking all court costs plus the agreed amount. I was paid two days later and I don't really talk to him anymore.
The First Sergeant is probably your best bet right now. Make sure you have reciepts and any emails or other transactions available to prove any doubt in anyones eyes.