EFT Payment

On 25 September 2015 I paid my account R856 via EFT, then the following month October 2015, I received calls that my account is in arrears, then I sent them proof of payment but they chose to ignore it and my billing was showing that my account is in arrears. Instead of calling me they only send me smses that I'm in arrears.I decided not to pay October month end until this issue is resolved. According to my knowledge my account is in arrears with one month. Can they please do a thorough check on their statements and balance sheets to trace that R856 and read the emails.