Selling me unwanted goods!

I am a owner of a small hairdressing salon in Woodlands Pietermaritzburg ,I had ordered from a telesales agent, ink cartridges earlier in the year .To my understanding it was a once off in which I had paid for after delivery. They then sent me another package which I had returned simply because I did not order anymore .They then called me up and told me that the deal was two packages ,I argued with the lady telling her that I made no such deal ,she told me that there must have been a misunderstanding, and that the deal is the two packages . I then just excepted and they were sent back to me I paid for it only now in august, the week after I paid I received a call from them thanking me for the payment and they will be sending e the next parcel, I told them I do not want any more of this ink that I still have the other that they had sent me , that have not used it as I am not an internet caf?'. They are insisting that I have to take it and that its part of the deal. Please can you help me as these are expensive.<br> They told me that they had a recording of our conversation and when the manager phoned me he said that they don't do voice recordings.