2014 AIRSTREAM INTERSTATE Unknown Or Other Problems

I test drove a black Sprinter (with everything working) in June 2022, and I subsequently mailed a $5,000 deposit in June 2022, to have the vehicle removed off the inventory lot until I tendered the balance. I came to the dealership on [XXX], to purchase the Sprinter that I test drove; and the radio, front tv, rear bench seat, back up camera and step was not working properly. They instructed me to take the RV to a local Georgia location (where I live). Upon inspection and diagnosis Multiple problems found that all need to be addressed. For some unknown reason a jumper wire had been installed between the chassis batteries and the coach batteries. I can only assume this was used to trick the inverter into charging even when the coach batteries were low. This wire needs to be removed. Incorrect batteries. The unit has 2 wet cell batteries, these...