Refuse to catering express of R900

Mr Goodford asked me to arrange a training session for Multisure sales agents that I have invited for 25th August 2015 I contacted him regarding price for venue R400 and R45 per head charge for the 20 people I have invited to attend for refreshments. costs included hiring of equipment coffee, tea, biscuits and sandwiches and labor. he conformed that it will be no problem that its fine. he paid the hall after a long debate. on Monday the 7th September I sent him an email with invoice and I contacted him to ask if he he received my email he said he had not read his emails yet but he will pay before close of business on Monday. than on Thursday the 10th September I told him he has still not paid the R900 and than he asked the account umber and said he will pay it now ..he sent me 3 sms for the account number so I had sent it to him and emailed the invoice again but than he said that I will have to take the matter to their finance department because his unable to pay because his not sure if they will pay him back. I have all his sms on record and what's app messages promising that he will pay the money. he asked me now not to take the matter further and changing his story.