I believe your rack was simply not centered when the alignment was done. Starting with the steering wheel level, turn the wheel to lock and note the exact end position. Then do the same in the other direction. If the steering wheel positions are not the same then the rack was not centered when the alignment was done.

To correct the problem the alignment must be redone with the wheel centered. Apparently the shop tried to correct the centering by simply eye balling it by turning the tie rods (the rack's end links that connect to the road wheels). Even if they had hit the center point the rest of the alignment settings wood still have to be performed because all the adjustments are interactive.

I would take it to another shop and not say anything except that you think you need an alignment because the wheel is not straight. If they are successful, take the receipt and printout to the first shop and ask for a refund.