So very disappointed at the LACK OF SERVICE!!

So very disappointed at the LACK OF SERVICE!!
Traveling with my daughter and a horse and diesel motorhome engine lights both come on. Got a place to stall the horse and went straight to this place. Was thrilled they could work in the rv, I thought!!
After 4 hrs of waiting, I went to the desk to see what progress had be made. My rv was outside and no one had come to talk to me until I asked. Mechanic told me I had diesel in my def tank and the whole unit needed to be replaced. He asked if I was the last one to fill def tank and how it can be confusing at the gas pumps. A-HOLE
We always buy our def out the blue box and have never filled at the pumps, so we knew it wasn't possible to have diesel in the def tank. So I asked if they would siphon out old def and fill with new. Our home mechanic told us that def expires and gets ruined in cold weather. Which made perfect sense!
Mechanics at this place told me I would have to wait another 3 HOURS, for them to drive my rv back inside to do the 5 minute siphon and refill!!!
I LEFT, HORRIBLE LACK OF SERVICE!!!! SHAME ON YOU CHARGED $300.00 AND 5 HRS OF WAITING TO BE TREATED SO POORLY!!!!
MAYBE YOU SHOULD TAKE MY 300 DOLLARS AND SEND YOUR MECHANICS BACK TO SCHOOL!!!!