Telkom expects payment when they can't deliver

Telkom has delivered a package for me which I took out for Netflix in which they have given me 3 months free but only after they billed me for the second invoice did they deliver the lit box that allows me to get Netflix. I refuse to pay the invoices because they did not deliver on what i required and everytime you contact them they say it takes 7 to 14 days for a response but nothing happens. I would like to get my service I requested and then i will take on the payment which is my 3 months free if they can't do that i dont want they services