Overcharged for the second time

Last month had been overcharged by mrpmobile,I contacted them they said its not them but they will look to the meter and comeback to me. So I did pay for that invoice despite the fact that I was not contacted . And now they had send another huge invoice again ,when I call they said their are going to come back to me. They are claiming that am subscribe to another company and they gave me numbers those people said am not on the subscribing list I must talk to my service provider.<br> This people are making my life a living hell,the are ripping me off. I want to cancel the contact with them still they said some one will contact me and help me but no one did. They just take my money and this thing started just after I had stop using their simcard . I want the some one from management to sort this thing out please