Your unfortunate situation could be the result of so many things: the person on Chat (likely from a 3rd world country), thought a Hopper was like a ViP gave your the wrong response as so many of those in the Chat/Call centers are OUT of the US and almost NEVER get it right; a statement of "a simple wiring issue" could mean so many things as in one thing to them, and one thing to you; other miscommunications or misunderstandings, ignorance or even a fib.
Agreed, Dish should see to it that people and installs all go 100 percent as customers expect, but with all the outsourcing of CSR and Chats, it is less likely today than ever. Ironically I AVOID Chat whenever possible because like the phone CSR's, you will be chatting with someone in India or what other 3rd world country who may have NO clue how things really work outside of the big notebook of answers they have. With Dish, and many other services, you are far better off requesting a phone CSR in the USA, and they are the most often (not always) correct.
It is true that mirroring is NOT part of any standard Dish install. Most often, you can arrange such an EXTRA service as "mirroring" with a local retailer, or you can ask the installer who shows up if he is willing to do the work, and if it won't take too much time, he may do so being a nice person AS A COURTESY, but I would certainly TIP him for his labor beyond any services of a "standard install," unless Dish specifically charges you for the additional mirror service install, but as a rule, Dish doesn't do "mirroring" installs. Keep in mind the Hopper is a whole home DVR, and from the engineers and Dish's point of view, their Hopper system addresses mirroring. But, of course, there are situations as yours where mirroring makes much more sense than an extra $7 per month for only occasional use.
Now, let's move forward, and it is true that it really is a "simple matter of wiring." As stated, a 3rd party RF modulator needs to be connected to the Hopper (or Joey, if you wish) and then use coax between the RF modulator and your TV. Happy viewing.