Sbi Fastag — Service and Refund

Address:

D No7-14/3-6, Near Diamond Park, New Colony, Srikakakulam

I have bought SBI Fastag from SBI Agent for INR 600/- and it was not working properly, contacted the agent for the same and received worst response from the agent, so mailed to SBI Fastag department with the details on December 19, 2020 and till date not received any response.
Tried so many times to customer care and discussed the same, but no use and my Fastag not working, so I was surrendered my tag on January 30, 201 and it was approved on February 3, 2021 wide reference number SBIFTCL129557120210130173258.
Till today the refund amount not credited my account.