NISSAN / DATSUN REALLY SUCKS

I bought a datsun, had some issues with it. Broke down and complained on Hello Peter about their roadside assist. I finally got helped and my car was towed way out to Springs, far away from where I live. I got a quote to replace the battery as per the warranty. One month later I get a call saying I was quoted incorrectly and If I could please pay the difference. Being nice, I said yes. A panel was removed from my car whilst in Nissan Possession. I have not received that Panel, But I got a call today stating that If I do not pay the difference for the battery, Legal actions will be taken. The nerve of Nissan.<br> My car is giving more problems now, and I am worried, if I take the car to Nissan for check up what else will go missing from my car, and after one month will I get a call saying I owe more money. <br> <br> Checking with my lawyer if legal actions can be taken for theft against Nissan for the panel in my car that is now missing.