2007 Equinox Transmission problems?

My 2007 equinox is: When changing from P to D sounds and feels rough, slipping from 1-2 gear most of the time, 3-4 gear sometimes. At highway speed when I press the pedal sometimes you only see the RPM go up and a few seconds later the gear enters hard. Sometimes it makes a loud metallic sound when it changes gears. I changed sparkplugs and wires, got better but the problem still remains.
A year ago I changed acceleration valve body, it got better for a few months.:confused:
Please help someone!!!!!!

Any slippage of the trans is an internal problem, you could try changing the fluid and filter and look for any debris in the pan.

My equinox has been with the mechanic for the last 15 days, he took down the transmission and told he changed filter, and found no real internal damage, changed valve body (again after the first one a year ago), but still continues with the same problem when in 3rd gear.
He tells me he "thinks" it could be the module,:crying:
At this moment I think they have no idea,,,,,
And my Equinox still does not work,,,,,, and at this moment the bill is up to $2,300 dollars!!!!
HELP PLEASE!!!!

This a transmission shop? Local or chain?