bad service from such a big company

i now don't know what to do with Telkom , I have again received the wrong bill , my bill must be R556 but Telkom is billing me R1000 which I don't know where the other R500 is coming from , I went to the store and ask if my account is in order an I was told everything is fine only to be surprised by the bill no , I mean this is not the first time I have to go through this problem with Telkom , I work very very hard for my money only to be ****** by this big company in day light , I think I must take this to social media now maybe they help when the whole world is listening and watching . **** Telkom