Online SBI — double paid amount in erd account

Address:

Bongaigaon, Assam

dear sir i open a erd account through my sbi saving account online in Aug' 01.08.14 amount Rs. 4200 p.m. i paid first instalment on 01.9.14 and paid second instalment on 31.09.14 for the month of sept'14 in advance through my internet banking account.but on 01.09.14 bank again deposit another 4200 ruppess from my saving account, they not refund my amount its double transaction. my saving account in SBI New bongaigaon branch, assam, IFC Code. sbi0007997.please give my money of Rs. 4200 back to my saving account.