Telkom suspended their service but is still charging me

I went over from Telkom to Vodacom home fiber. I didn't phone to inform them on time and I got behind with my instalment but never the less they handed me over to they Debt collection department. Debt In contacted me on the 25 April to make payments, I struggled with funds but eventually did the payment on the 24 May, the outstanding amount was R1369.30 but I paid R1400. Now when I phone to find out if the payment was received the debt department was not getting back to me at all. I went to Telkom in the mall here in Cradlestone and a friendly lady called Kgomotso helped me. Only to be told yes she sees that payment was done but I still owe R619.23, how is that possible if handed over to their Debt department? I don't use their services no more and it was suspended but they charge me🤔🙆. Telkom isn't making sense to charge me for suspended services. I'm using Vodacom home fiber since March.