Firstcry.com — delay in refund

I had returned a product worth Rs. 1304 for which I was supposed to receive a refund. Due to their system issues, firstcry initiated the refund in 5 separate amount which should be in total 1304, however I received only 628 from them. Now they are asking me for a statement and when I contacted the bank, they asked me to get ARN number from firstcry but they failed to provide that. They should not only refund me the remaining balance but pay for the time I have spent calling and emailing them. I have been a customer for 6 years and they still do not have the courtesy to take up the matter on priority.