You could take it back and have the tech recheck the allignment and see if it is the same as the adjustments. If so you could return it to the stock settings and try that. if it still pulls it could be an issue with the electric steering since the force feels different from left to right. Let the tech drive it that did the allignment. That is the most bothering problem when you have to take it back and forth to the mechanic to try and resolve an issue. I've been there done that with my 2010 SS.
Sometimes dreams do come true.