Vintage dr marten platform sandals purple/burgundy UK 5/ US 7

I recently bought these and love them but they don’t fit ;( I’ve never worn them out they’re in good condition :)). I have no box. Does have some stains from metal buckles (that’s how I received them , previous seller has had them storage away) not sure if they will come off but doesn’t show if buckle is placed where the visible stain is :). Overall super cute sandal for summer !! :)) <3 Send me questions! Crossposted :))