My foot was cut i went to the doctor he gave sitches and antibiotics name augmentin (amoxicillin and clavulanate) but nrxt day my foot swell up big what could cause this

Couple of reasons:: 1: the bandage might be tight, so loosen it somewhat, and elevate the foot; 2: Allergy to some of the locally applied ointment/antiseptic; 3: further bleeding from a cut blood vessel. I feel the commonest cause is Tight bandage, as when we move our foot ot toes, the Acewrap/Crepe bandage gets bunched up making it tight, and so swelling occurs. See your treating Doc if not improving. Good Luck.