Not getting the service we pay for

I have phoned Konica Minolta Alberton on Wednesday 8 April 2015 and ordered all the toners for our Printer machine. They told me that it will be delivered on the Thursday ( 9th April 2015). The toners were only delivered on Tuesday ( 14th April 2015) but still no black color. When I phoned they said there was a problem with the black and that it will be delivered on the Wednesday, 15th April 2015. We still have not received the black toner. We are not able to print for a week now. I am definetly not going to renew my contract with them