Disappointing service

I bought shoes from the fix at The Glen today. Only when i got home did i realise that they did't remove the security tag on them and i'm suppose to wear them tomorrow and now I'm unable to remove the tag because i believe the is a special magnet instore designed to remove these tags. Firstly i'm disappointed at the ignorance of the cashier and to my understanding those machines at the door are suppose to make some sort of sound when you pass with an item without removing the security tag. So those things have just proven to be totally useless. Now i have to drive all the way back to the mall to remove that tag and pay the mall parking with my money. This is not on cashiers must pay better attention when doing their job