Faulty Wi Fi Router

I was contacted by a pleasant, efficient Sales person and agreed to a contract for a Wi Fi Router. Firstly I was not advised by the courier or Vodacom as to when it would be delivered so I missed the first delivery. and delivery was on the 29th Jan.Then it would not work and kept advising me there was a Sim Card Error, so I took it into a Vodacom Shop on the 31st January to be tested and was informed it was faulty but that as it was sold via Direct Marketing I had to deal with them and the shop could not replace it. I sent an e-mail on the first February explaining the problem and apart from some form e-mails and a couple of standard sms's nothing at all happened until suddenly the couriers arrived about 12 days later and said I must return everything and gave me a replacement but there was no new Sim card supp**** and no one advised me to keep the original Sim, since then I have written to them multiple times and still nothing has happened. I did receive their invoice promptly though!!!