I have not personally been through this, but I have seen accounts in my area go through this, some with success, and some without...and with various vendors, not targeting anyone. So with that said:
You may already be doing this, but start documenting EVERYTHING. Have a log showing when you placed a call, then make the tech sign it when he arrives noting the date/time, and have another column where he signs/prints his name that it was resolved. This will help prove they are not holding up to their promises. The log should also have a place to write the current meter reading to show how little amount of prints you're able to get between CPC's. Don't rely on the techs writing this down because they often run dozens if not hundreds of impressions during a service call to run tests. Along these lines, you may also want to track those clicks and see if you're being charged for those service test clicks. Normally you do pay for them, but based on the amount of issues you're having, the machine might be a lemon and you shouldn't have to pay for excessive test prints.
You might also want to review if you have actual documentation guaranteeing a 4hr response. In my experience, every vendor's sales rep will verbally say this is the average, but they don't always guarantee it in writing. You should have received a 'Customer Expectation Booklet' or similarly named document which might have something related to this.
Typically, you will have to give the vendor a chance to replace the machine in case it may be a lemon. If the machine is really not meeting what the specs say it will do (meaning it won't actually staple 50 sheets in a 50 sheet stapler, or won't duplex approved 350gsm media when the specs say it will) then you'll have a stronger case. If you just don't like the quality/look of photos, that is quite subjective and they could argue that you had a chance to do a demo and run test prints before you bought it.