Not happy with telkom

Hi i had a data contract with Telkom given a small unit for me to have that data it's a problem now i am receiving sms on my fone that i still owe them again . I last paid their amount of +-160 last month now they need another amount of 202.70 .I am so disappointed by this company they want me to pay for 4 years on a three year contract. What do you really need from me. I am Busisiwe Zitha on ***.