Mweb is worst than telkom

Second bad service post about mweb in one month since I joined. When my internet was finnaly working I noticed that it only shows 51.64gig (I'm supposed to get 100gig) I thought it was because I joined in the middel of the month and that I will only be billed for the data I get. Received my statement now and saw I must pay over R700(my subscription is for R530). I then went online to the live chat and spoke to Noel, he said I only get that 51gig because I joined in the middel of the month but I must pay the full amount and that is how they work. This is unacceptable, I want my other 49gig I paid for or I'm canceling with mweb. At least Noel gave good service.