Billing of closed account

I close my Internet account in October fourth was the first email the 26 was the last I paid 30 day notice and thought that was the end of my worries but surprise surprise in December of 2017 I got a bill I Ponty phone Telkom and explain to them the count has been closed The consultant asked me to forward the email I sent to close the account to her so I did then later in the week I received an SMS saying the query will be processed and then I thought to myself surely this must be the end of it but then again in January of 2017 I received another bill adding onto the bill of December So I phone them again and spoke to a lady who promised me that by end of business day the matter would be sorted but yet again they failed to deliver now today I phone them again and they said in 10 working days the matter will be sorted meanwhile my credit record shows that I haven’t paid my account in two months giving me a bad credit record stopping me from find the finance for the house I’m about to buyI don’t know what to do anymore legal seems to be the only option this is the last time in my life time that I will do business with Telkom I am utterly disappointed by the horrible service