Tata Tele-services sending emails to pay additional amount for services not used

Location/place: Chennai

Name of company/service: Tata Photon

Complaint on Tata Photon + 9281006556

Hello,
Complaint on Tata Photon +
Acc No:- 918078639
Del No:- 9281006556

I had taken Tata docomo connection paying two months advance rental which is Rs1500/- after which I have was provided connection

Activation date was on 15th March
On 19th March Raised a complaint # 35392547 for not getting bandwidth but was never resolved, received couple of SMS that it will be resolved within 2 days never got it resolved

On 12 April raised Complaint # 355933119 for cancellation as was not getting bandwidth for which cancellation was completed.

Now, I have used the service for less that 1 month and had already paid 1500 as 2 months advance there is additional amount of 750 with tata tele-services

I have received email on June 15th from Vani Ravi 2nd level escalation as per email that i need to pay a amount of 1460 as per billed amount and if skipped a legal action would be taken ..
I sent an email to Vani ravi & called her on June 15th explaining the same she assured me that it will be taken care and ill not receive any email or calls from tata tele-services

Today on July 13th i received an email from VANI RAVI again stating that i need to pay a amount on 1460 and need to contact legal advisor R. SIVAKUMAR, B.A.BL.,

I’m confused why did i receive email from Tata tele-services when i was promised it ould be taken care
and also why should i pay the amount when there is additional amount with tata-teleservices and they even called me and informed that they would be collecting back by tata photon device shortly.

Any help would be appreciated

Thanks
Anil
+919962216205