Indian Oil Corporation [IOC] — Asked to fill Petrol for Rs. 950 but bill slip given only for 650.

Address:

Sarita Vihar near IGL CNG statio

At Sarita Vihar IOCL petrol pump, I asked the attendant to fill Petrol for Rs. 950 but he first filled for Rs.300 and then distracted me for change of rupees and without making me check zero again, started refilling and total filled up for Rs. 650 only and refused to give me bill for total amount of Rs. 950.
I was given a receipt of Rs. 650 only saying it cannot be generated as zero has already been adjusted.