I'm usually a technical, nut-and-bolts guy, as far as offering any advice here, but with 30 years of sales-management experience, I'd like to help on this subject if I can.
I can't help but be curious about...
1) The T&C's of your purchase order.
2) The explanation(s) given to you for the delivery/installation delay(s).
3) If this is an example of their Sales-Department service, what kind of response can you expect from their Service-Department?
4) How you have somehow managed for 7 months without this machine?. (Do you really need it and have you examined other sources?)