Pipes cause noise in Gearbox???

Good morning<br> <br> This is not to complain for the sake of complaining, however I feel my issue is falling on deaf ears.<br> <br> I booked my car for its 30 000km service on the 27th of May. I indicated to Rachel that the service needed to be done, as well as check a noise coming from the gearbox. As if my car is in gear it makes a noise, but push the clutch in or put the car in neutral, the noise goes away.<br> The service was done and the mechanic/workshop manager came and said \they normally replace the transmission oil to fix that noise". He proceeded to replace the transmission oil and went for a drive. He came back and said that the noise was not gone and would have to ask Mervyn. I said"