Vodafone - Wrongly charged due to Store Executives mistake

Recently in the month of January ****, I received my bill and I was surprised to see that the bill was Rs ****.**, and my usual bill is around Rs ***.
I went and checked with the store and I was told that I used the Internet that is the reason I was charged so much. The background of this is I have been visiting Vodafone store at Dattamandir signal, Nasik road, Maharashtra since October and November on a monthly basis to complaint about their network and internet not working the first month they said they will file a complaint and someone will call and resolve the issue, but no calls came through or nor the issue was resolved. Again in the month of December I visited the store and complained about the Network and internet issue, the store executive said its an issue with my phone and not their service and asked to see my phone, so I handed the phone to the executive, he without even asking or telling me changed the settings in my phone. I forgot to tell you I use One Plus * T which had a dual sim and I use my Primary number for the Internet and the other number ********** is hardly use and because of that I never had any internet service on it. This executive changed my from Sim* to Sim * in Internet Settings .. I still had no clue, nor did he tell me. He asked me to check if its working and I went back home, I started getting Sms for internet usage, from **rd or **th Dec and being a Christmas week I was with my family celebrating and in the first week of January precisely on the *th of Jan I went back to the store to complain about the network and about receiving these messages. The executive told me about my settings being changed and he showed me. I said ok and left thinking it might be billed but I never thought the bill will be this much. I went back to the executive and he said that it was my mistake and I had to pay, I was taken back as this was done by the Vodafone executive, anyways I wrote to Vodafone customer care on the *th of February explaining them the details to. I received an email saying it will be resolved by the *th of February and since then I wrote to them at least *-** times getting different people some saying I misguided the executive some saying something else. I was hounded with at least **-** calls a day from Kolkatta, Navi Mumbai, Mumbai, Pune on an hourly, daily basis. The issue remained the same but the torture kept increasing on daily basis. I had to explain my on every call my issue but they hardly bothered about my issue. In the month of February, I made a payment of Rs ***, and the same day my outgoing was barred. My daughter was hospitalized and these people were calling, again and again, I explained to them that I'm in the hospital going through surgery that's when they stopped calling for *-* days. After that again the calling started and the volume had increased by **% I would say. So I stopped taking any calls. Today I just checked the phone and my incoming has also been barred. I can't take it anymore so I'm filing a complaint against Vodafone.