Afrihost cheating in terms of data usage

Afrihost is looting customer by wrongly showing that use has used his data and asking to do top ups. I have been iburst customer for years and data was never finished within a month,but now since I have been migrated to Afrihost,the very first month,on 23rd April they said I have utilized all my data (20GB) and I need to top up,so I did a top up on 24th April with 5GB,now within one day on 26th they again saying I have used that 5GB as well,we are not even at home during the day ,only user internet in even for browsing,not even download huge data. I think its just their malpractice to get more money from user by means of top ups. Really disappointing.