State Bank Of India [SBI] — SBI Fastag issue

Hi - I have a complaint about SBI Bank's Fasttag. There is a SBI Bank's fast tag issued on my car's number in 2017. However, I have been using Paytm's fasttag all this while and I never knew that SBI's fasttag was issued because I never requested for it.
Now, I have been trying to get a new fasttag and got my Paytm's fasttag closed and during this process I came to know that SBI's fasttag is also issued on my car's number.
I have never received any fast tag form SBI and never used.
I want to get this closed so that I can get a new one issued on my car from a different bank which I can use as well.
But it has been really unpleasant experience to get the fasttag of SBI closed.
I logged into SBI's fast tag website and it doesn't allow to close it because its asking to make a payment of Rs 70. Which I am okay to pay so that this tag can be closed. However, when I try to make the payment then it doesn't allow to make the payment.
Then I raised a Complaint on the same website, However, I haven't received any acknowledgement or Complaint number from SBI bank fast tag department. I don't know where to connect and get this issue resolved.
Then I called the helpdesk number mentioned on the website. Firstly it took me 2 days and 7-8 calls for someone to pick my call. Eventually when my call was addressed, the lady gave me an agent's number who is supposed to activate my fasttag only after that I can make the payment of Rs. 70 in order to get the tag closed. Now I have tried calling that agent a couple of times but he is not picking my call.
I really need help with this as currently I don't have an active fast tag which is creating a lot of issues for me and unable to travel because of this issue.
Kindly help.