Rear of car is higher one side than the other after fitting lowering springs

Any one else had this problem - if so how did you solve??

I had springs fitted last friday - looks amazing from one side, drives perfectly, handles fine but the passenger side sits about 10mm higher at the back than the drivers side and is bothering the hell out of me

My mechanic thinks im nuts but Im 100% sure its different - I can see the writing on one of the springs is facing rearwards but the other is facing the opposite direction - would this make any difference?
I know the bottom of the coil is sort of cut off so my thinking is that if the cut off part is at the back of the platform the car would be lower than if the spring is fitted the other way round so the cut off is at the front of the platform

Any help would be much appreciated - I hate the week before FCS - always so stressful!

Thanks
Tim

 

can anyone confirm this^^??