Faulty printer help please!

Hi I have been reading up on consumer law but am still unsure where I stand on the issue of significant inconvenience-I'll explain the situation:

Our Epson printer stopped printing black after only 3 months and on contacting the retailer, OYYY, I was told to contact Epson which I now know was wrong! Eventually OYYY agreed to collect the printer and take it to the repair centre and return it, a process which took 9 weeks as they took so long to reply to me every time and told me I would need to return it with ink for them to test! The original printer was faulty and was replaced and the new one arrived-guess what? It didn't print black properly from the start and stopped printing colours the next day(there are lots of cases of this with this model so it seems to be a known fault) and now I'm being fobbed off yet again with promised phone calls that never happen.
What are my rights in this situation as I have now been 10 weeks with no printer and don't want the same model again as the same thing might happen-OYYY say I am not entitled to a refund at this stage but surely this situation counts as significant inconvenience? I've also lost £40+ of ink from doing head cleaning as I was advised.Any advice would be much appreciated-oh and avoid the Epson SX600W printer!

Thanks for the reply-supposing this one needs replaced do I have to accept the same model knowing that this is a common fault with this printer? The same thing could happen again once it is outside the first 6 months. The one I have now is a replacement not a repair of the original. Also do they have the right to ask that I return the printer with my ink in it?

I thought the onus was on the retailer to prove the machine was faulty within the first six months? I don't see how it is reasonable to expect me to provide £30 of ink for them to waste even more-head cleaning these faulty machines using about a quarter of a cartridge each time,more than normal.Surely it's up to OYYY to return the printer to Epson where they can test it using their own ink?I can't seem to find anything about the fact that the model has a known fault and where I stand on that-I'd happily accept a cheaper model that didn't block and actually printed!