There should be a disc with the hooks on the mat and a disc on the carpet with the ring part of the velcro so that the two discs come together. The discs on the floor of the car are actually screwed in.
Do you have that?
2014 EBII 435i xDrive M-sport
Gone: 2011 TiAg F25 X3 xDrive35i M-sport
Gone: 2008 TiAg w/Coral Red E88 135i Cab M-sport