Punjab State Power Corporation [PSPCL] — Deduction of more money than actual bill amount from bank account.

Address: 152002

I paid my electricity bill to pspcl through my debit card. the bill amount was 6790 but when i paid bill through my debit card, the amount deducted was 6860. but company webpage shows deduction of only 6790 rupee. i also have pdf file of same page showing deduction of rupee 6790 rupee. why that extra 70 rupee are deducted along with actual bill amount. on hard copy of electricity bill as well on company's website it is not mentioned, that extra charges have to be paid if bill have to pay online.