Lotus Print Consumables (Pty) Ltd - BAD NEWS!!!!

I have been harassed and threatened by this company for 6 months. We are a small company and they insist that I ordered 18 print cartridges which cost 3 x the amount of a normal cartridge. When I asked for proof of a purchase order, I was informed that they do not work with purchase orders and they have now invoiced me for "discount" which they claim I was given. They also claim to be a part of Essential Group as a preferred supplier! STAY AWAY FROM THESE PEOPLE!