Very disappointed

I have 2 data bundle SIM cards 1 SIM only contract and a cellphone contract at Telkom but in August they charged me for additional data used whereas I do not use the sim only contract for data .I have 2 Sims in each cellphone and I am surprised that as per my usage billing both Sims on 1 cellphone had data being used simultaneously and I was billed for it. Really disappointed with Telkom. When contract was taken with Telkom I did ask for a top up contract and not an open line . Telkom has a spend limit facility which I asked the consultant to put it at zero and he did say he did so how was I billed for excess usage. TELKOM NEEDS TO LISTEN TO THEIR SALES AND UPGRADE AGENTS CALLS AS MANY CUSTOMERS ARE BEING MISLED.