Paid the account yet account not debited

I paid my Telkom account on the 15.03.2016, my account was cut and when i received the statement there was no record of the amount i had paid. Since then i have been in contact with an agent over email, who refuses to assist as she says i must call in. How they expect me to call in i have no idea, as my cellphone line has been cut. this is ridiculous i have had endless problems with this mobile network and i intend to cancel this contract at the end of October.