Telkom

Good day,in September I signed a contract with mondo telkom for 2samsungs for 380 per month but payment they wanted for December is not what we discussed when they phoned.31desember they debited a total of R595 and the same day reversed that amount and only transferred a total of 390 from my acc to telkom.today I recieved a msg that my acc is overdue.Something I dont understand because our arrangement was that I only have to pay R380 per month