Trade-in value dropped to zero for no reason I understand

i prepared my early 2016 plain-Jane MacBook for a trade-in according to the instructions. Everything went accordingly. The hard drive was encrypted originally, I had been using a VPN, and the machine was used only as a second machine when visiting clients. Never modified it, never did anything special besides updating the OS and Microsoft Office. Now I am told that its trade-in value is zero because it was jail-broken, and data erasure was unsuccessful… I erase the hard drive… and reset the device.

Anyway to appeal? This makes no sense.