Audi Allroad 2.7t manual trnasmission fail?

[ti666]

Hello to everyone! I bought audi allroad 4bh/c5 2.7t manual transmission and I had to change the clutch 3 months ago. Did it in local garage and 1 week ago while I was in the motorway with approx 80 miles per hour I heard a sound. After that the car wasn't able to shift at all. I stopped at the hard shoulder. The gear lever was stuck in 6th gear. I tried and forced it to neutral then tried to start the car but was reacting like I'm in gear(so I guess it's stuck in 6th gear). After that I start the engine with clutch pressed but no luck when trying to shift. I called RAC and transport the car to the same garage I changed the clutch. The wired thing was that even with clutch pressed car wasn't moving. The guy from the garage told me that the fault was in the gearbox and needs to be replaced. He told me that he found one on ebay for 2000 ponds. So I would like to ask if it sound like a gearbox fault or the link between gearbox and the lever(because the RAC guy told me that that was the problem). Thanks in advance

[R490]

I'd say a linkage, or lack of transmission fluid.

[ti666]

If it's a linkage than it's easier to fix right? But if it's a fluid lack than that means that the gearbox is gone and it has to be replaced or reconditioned(which maybe will cost more than the car itself and that's sad because I really love that car).

[ti666]

But either way I may have to change the garage and seek 2nd opinion about it.