Water in Petrol, terrible owner - Total Garage Kempton Gate

terrible experience , petrol was mixed with water ,i guess because of the heavy rains, but the owner did not acknowledge that , he said a statement like he does not sell water, i was one of the unlucky customers that got petrol mixed with water, i was so disappointed with his response as the car had an issue and machanic pumped out all the petrol i went with it in container as proof, he dismissed me saying he will come back to me , but i know he wont based on his attitude so will take it further, the least i need was my money back , not even asking for him to pay the cost of the mechanic, i feel is