'Worst service, most annoying telesales EVER

This place is so infuriating, about 2 months ago they phoned to sell me ink cartridges. This guy went on and on and on after i told them i don't use much ink, i used a pack every 4-5weeks as i dont print much & the double pack cost me R500. But after much nagging that went on for roughly 25min & he said the cartridge last 3 times longer, i said he can send it, just to get him to shut up. Thought i will just return it the second it gets here. SO the cartridges arrive like 2 days later, they sent 4 cartridges at a shocking price of R3215.00!!!!!!!! I told them i refuse to pay this i WILL send it back, then they say they dont take returns!! The lady Brenda phone several times almost every single day for the last 3 weeks asking for payment, i told her i have not used any of the cartridges, where i was told i can try the cartridges first and then pay!! Well according to her, i MUST pay it.. So eventually last week my original ink ran out so i put one of theirs in, well to my surprise a week later that one is low?? So where does this "oil based"cartridge last longer. She still phones me daily for payment when we have agreed that i pay it over 2 months. I am so sick of that place and that woman.