Bharti Airtel - delay in service

bought airtel xstream fiber connection. on **th August **** after ** days Internet stopped working so I raised complaint on *th September expected time for resolution was *th September **;** am ....but no one came to fix it and no one contacted me so I called their costumer service
they told me to wait for * hrs and said their team will contact me....after * hrs no one contacted from their team I called again and again ....called them more than ** time and every customer executive keep repeating the same thing "we have highlighted and escalated your complaint wait for next * hours our team will contact you" but I didn't get any tcalls from their side....every time I call they put my call on hold for more than ** minutes and their local executives are not answering my calls either ....at *:** pm I called them again now they are telling me that I have to wait till tomorrow ....I've contacted them on twitter but still no response....before taking connection they promised me that any grievances will be solved within **hrs ...please help me my studies depend on it