Uh yeeaah!

I dropped my Allen & Heath Xone 02 mixer off at Just Audio, on Harford Road in Baltimore, for servicing because the (highly regarded) Penny & Giles crossfader began bleeding a week ago. Today, I get a call from the shop's tech. He asks me what's the problem with the mixer. After I tell him, he says well It's working fine now. Do you want me to order a new crossfader and install it. Uh yeeaah! I mean I've had the mixer for a month or so and know that it wasn't doing that in the begining, but now it is. So why would I take the mixer back in the same condition for the same problem to occur shortly in the future? This brings me to my point. When something is not working properly, and you take it to be fixed, the problem is rarely fixed (or even diagnosed) on the first visit and I know why. Because that tech, who is not a DJ (or at least a scratch DJ), is not going to use the Xone 02 mixer the way that I use it and therefore he will not be able to replicate the problem. The same goes for that car mechanic who is not going to drive your car the same way that you drive it daily. So why don't service shops allow you, the owner of said equipment, to show them the problem that is occurring so that it can be fixed correctly the first time? I don't know the answer to that question, but hit me up if you do.