gearbox leak

[A8 Owner]

Hi Mrs A8 Owner here
Just been told by my gearbox has a leak,
Stev thought there might be due to the hot smell we get after a trip out, hence why i had it checked out. Weird thing is we have had this smell since we have owned the car, yet the transmission people who did oil and filter change on it didnt say a thing to me.
It seems at the back of the gearbox, high up theres a leak, poss seal gone. Anyone on here can confirm theres a seal there, or is there somthink else to look for?. Is it big job to do?, I.E lots more money?
Will be ringing transmission people tomorrow to ask why they didnt tell me about this, as it will mean ile havto payout again for oil.
any help greatfull.
Thanks
51 plate FL 3.7 sport 5 speed
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