Great Clips — theft

I went to great clips here in Longmont, Colorado up on Hover Road
Got my hair cut with a coupon of $6.99 and left $3.00 tip for a total of
$10.00 but when checked my bank account it read Great Clips had
charged me $11.99. I do NOT appreciate being stolen from. It got
addressed the manager is sending a coupon for free hair cut but
that is besides the point. No person should add extra to their benefit
and I am NOT a person that has money and everything I get is spent where
it needs to be spent without someone stealing from me...I am not a
happy person at this moment and yes it is just $2.00 but still.