Non payment

Print Experts contacted me to manufacture large aluminium sign booards for a chinese company at stellar warehouses crown mines jhb. I sent my quotation to which she agreed on after altering the price but I did agree and we manufactured her signs, my quotation also stated the balance of payment should be paid on the day of installation. Upon arrival, the one wall where the boards were to be installed was the correct size given, the other wall was incorrectly measured (not measured at all on her behalf)<br> She asked please please can I just take it back and cut it shorter. Totally not my fault but small heart I said I would do it as to create a good relationship with a new client. Still no payment as promised. I have returned immediately and corrected her mistake. This was November 2015. Today is February 23 2016 and still no outstanding payment has been received. Empty promises company to which they sub contract all the work and lift no finger. I can only imagine what she must charge the external companies and then on top of it not pay the actual company doing all the work from manufacture to fitment.