Vodafone India — I'm not happy with vodafone services

I was using vodafone services from last march 2017. But every month the bill of it has come around 800 something whenever my plan was only 499 and monthly bill should be come around 560. This process was going on continuously from last some months. When my last month's bill came to be of 1400 then i call customer care to correct the bill but at that time i didn’t get any response. I called in october last. After that we had to go my home town for a month. Between this time periods, we didn’t any call from vodafone no, because in november my incoming services had been closed. And at that time i was not getting any call from customer care. I did not use the number in november and december. Now they are calling me continuously for paying bill and asked to correct the bill after 2 months. I’m not happy with vodafone service. Why do they call when they do not listen to us?