In the decade plus that we've been full timing I have never hooked up to city service...
It was our first big adventure!... 2004/5 to Quartzsite AZ and extended stay!
I had a 3 filter filter system, (home built) to protect our water system!...This was one of those times that
"It's what you learn!.. After you know it all!.. That counts!"...
And I learned that first tank full of hot, sulfur, super mineralized, and corrosive desert springs of hell called water!...
That!...What I was doing!...Wasn't working! 
Before that first tank was used, (we drank bottled h2o) a couple showers, sink & head use, it was my second shower that had me running for a water specialist in the Q! ...I swear!... I was cleaner before the shower than after! My hair felt gritty & dirty, the shower door, (glass) was nearly opaque!..Calcium was accumulating like glue around fixtures!....Anyway!..It was horrible! ..... Not in Q or in business any longer, The Water Source installed a fully automatic R/O system in our DP! ... I drained what was left in the tank and it has never held any water that hasn't gone through the r/o system since! ... We also started drinking the water after about 500 gallons used!
You can probably tell, I'm sold on R/O!
So when we stepped into our new 38rssa (delivered to our winter spot) we didn't use it until I had R/O filling the tank!
Anyway!... you have warranty on your rig!... Get ahold of DRV and let them know how your dealer in treating you. Find a good RV service, a mobile service, someone legit to work on your rig!... Make a list of things that need done, what you had to do at your expense, and call DRV back. Tell them you've found a mobile, or legit RV service center, and see if they will work with them, (they do with friends of ours that bought at the same time) and get you taken care of!