Changed my contract set up with out my knowledge.

Telkom mobile has change the contract I have had for fours without my knowledge. I cannot make phone calls and text now because I am out of airtime but I have an opened contract with them, I have had it for four years. I called the call center and the gentleman told me I am out of airtime, the service was poor. I then spoke to someone on facebook yesterday and they promised feedback. This was yesterday morning. I am still waiting for them to respond to me. Telkom stuff does not respect the customers. i think it is just the culture at telkom to treat people llike ****. I have a landline and mobile with then, and you think I would get some kind of preferential treatment as a loyal customer but I get treated like ****. **** TELKOM.