MTN is a ****

MTN is a ****, I signed up for a contract of 15G a month for an amount of R169 ever since I've taken the contract I have only used less than 30G in more than 4 months but they charging double the amount every month. they are not sending any statement and this data I only use it once in a week some weeks I don't even use it because I have unlimited WiFi at home. they are ripping me off and I cant even get hold of them. their Whatsapp is not user friendly and n