TELKOM IT'S A ****

I have a contract with telkom, last month I called customer regarding my account and they told me February I must pay R199 instead of R250 as I paid more previously, so on the 16th I paid R200, and on 23 February I called telkom to confirm if they received the payment and they confirmed that they received payment and they owe me R.050 which they minus it on my next payment, and they gave me assurance that they will escalate the payment to collection department, but my account is up to date so will start to pay end of March, yesterday 04 March I received statement that I owe telkom R500 for February, how could I ****en owe telkom R500 yet I paid, so the money I paid they don't take it into consideration. Telkom it's a **** please ****en cancel your contract