Afrihost bad internet service

Please help me as i am with afrihost a internet provider most days they block my sim and say its been moved,it has never been moved my wife and kids are studying for degrees online and most times they miss the classes as this wifi is so bad but they bill me the full amount every month my mobile data works better than ther internet im so fed up with this and dnt know what to do anymore i shouldnt be billed for the full amount as the wifi is so bad most days really they suck i wouldnt reccomend anybody to go with afrihost its so demoralizing really pkease help they should know on ther side which days the wifi is bad and they should bill me accordingly please