Hi all - looking for some advice and comments please.
2021 A6 40TDI, 41,000 miles, recently had 2nd inspection and service with additional recommended gearbox oil and filter change, fuel filter and pollen filter.
Was advised by the dealership the car would need to sit for 4 hours prior to changing the fluid, but 3 hours after dropping the car off, I was advised all works were complete. 25 miles after collecting the car, the transmission warning light came on with the message 'reverse gear not available, you can continue driving' . I stopped the car, restarted, checked reverse gear and fault cleared. 10 miles later, the fault returned, together with a clunky change, missing 6th and very slow when using manual. This got worse so I returned to the dealership immediately - by the time I got there it was clearly struggling in any gear.
Dealership refused to accept it could be anything to do with their work, but prior to any fault finding, drained and refilled the gearbox oil without my consent. They then advised me the fault remained but wouldn't do any work until I authorised repairs because at 41,000 miles, it was over the 40,000 mile recommended service interval and therefore out of warranty.
Audi UK requested the dealership review the position and look to support but they refused, so now with The Motor Ombudsman.
Never had any issues with this car, or the previous A5 and looking for suggestions as to what the fault may be, and views as to whether it's likely, as I suspect, that the oil and filter change wasn't done properly, or with the correct oil ? I can't believe that it's a coincidence, or that a year old car with only motorway miles (still on first set of tyres, so driven very nicely!) would suddenly develop a fault for no reason.
Help !