State Bank Of India [SBI] — Complaint against taken wrong Emi. 2 Emi from one purchase in a month.

I am purchased a mobile phone of rs 16325 from amzon and converted into the emi of rs 2817 for 6 months. But SBI take one more emi of rs 2833 for the same amount. which is not done by me. It means I am paid two emi of same amount in same time. I contact to the sbi. Mail Sbi many times but no result come out for me. Sbi tell me that one Emi is from felxipay and another from merchant. But there should be only one Emi of rs 2817 which is i converted from sbi credit card application through flexipay option.