Forced to pay for goods we did not order

We received marketing calls from the above mentioned company with regards to ink cartridges that last longer than the current one we are using at the moment.<br> <br> We ordered only 1 cartridge to establish if the product is viable, which we received and paid the amount as invoiced. A few weeks later we received another 2 cartridges (10 July 2015) which we did not order. We called Siyakhula Products immediately telling them that we did not order these cartridges and that we only order the first one to test their products and to see if it last longer before we order more from them.<br> <br> They have told us that it is part of their introduction pack and that we have to pay for it. We have told them that this is not what was offered to us and that their marketing over the phone was false as they only offered 1 cartridge and we agreed only to purchase the 1 cartridge.<br> <br> (20 July 2015) We have spoken to Jacques who were aggressive and threatening to take it further if we do not accept or pay for the 2nd delivery. We have couriered the 2 cartridges back to their company, which they have refused to accept or sign for the delivery. <br>