Airtel - False commitment and harassment

I am using Airtel for last may be ** years or so. I had lodged multiple complaints in the past regarding the network issue but it was never resolved. They have also changed my postpaid plan to a higher plan without informing me. Considering all these issues I decided to Port out of Airtel and have sent the msg to Airtel for porting out on **th Feb ****. Immediately one of the representative called from the number ********** and convinced me to change my number to Airtel prepaid. To my bad luck I agreed. While he was on call I made the prorated payment till that day and he changed my number to prepaid. He assured me that I can recharge my number and can use it seamlessly. From that day until now I am not able to make calls as I can't recharge my phone it's been more than a week. Every time I call customer service they just logde a complaint and ask me to wait for *-* days. All my work is done through phone call or mobile internet and now I am not able to use my phone. It's affecting my work hugely. I can't even quote how much of money and mental peace I am loosing because of this. Can't change the number as it is linked with all my documents and accounts. Please help.