HDFC Bank Fastag — fastag purchase through hdfc is blacklisted

Team,

I have purchased fastag through HDFC . I am maintaining balance of 1500 as on date . I could not use it till date as it shows black listed in all the toll . tried raising complaint through customer care but always busy . No option to raise complaint through email .

my Tag Seq no is 10933422 . can i get some relief

Please help me to avoid purchasing one more fatsag as we are approaching dead line of Dec 15 .