If I'm reading this correctly, you had the tie rods (front end) replaced and an alignment done on all four? And now when you're driving high speed and making a turn your car fishtails..
Do you have any modifications done to the suspension? lowered? camber kits?
Since we don't have the full picture here, how's the tires?
What comes to mind is the following...
- Rear alignment incorrect, tires not sitting properly causing loss of traction on turns. The back wheels should always slant slightly so that on turns the wheel in the opposing direction sits flat.
- Sway bar disconnected/end links broken
- The bolts used for aligning are not tightening completely leaving them loose
I'm guessing the first point most likely, the mechanic would have to be retarded to not realize the last two but hey...I've seen my fair share

report back on what happens!