Billdesk — Frequent money deduction through billdesk

Address: Howrah, West Bengal, 711101

Website: billdesk

Actually i have been using this billdesk quite a long time...but now now this problem makes me so frustrated that when i make a payment on billdesk whether it is electricity bill or ibps or such competitive exam after making payment two days later extra payment got deducted from my account...why is this happen can anyone explain to me????seriously needed some information..
details of such payment
23/8/2016 billdesk ch no 16904003 amount 606.90
25/8/2016 billdesk ch no 52020599 amount 145.75
but i had not make any payment on that 25th////