Well sorry to hear about your issue
Not sure why the Dealership did not initially investigate where the oil was coming from

 

I had 2 significant oil leaks that caused me to have her towed twice. Both times (by Firestone) said it was hose lines breaking. I got sick after the second one because IT WAS ONLY A YEAR AFTER the first one. I recently saw small pools of oil showing up, so I took it to TirePros, which we have here in MN (a dedicated 4x4 shop) and they looked under but couldn't determine if the correct issue was founded but they did find a missing bolt for the "oil neck"? whatever that is. Since then haven't seen any leaking just the under looking dirty/ greasy. Oil life has decreased significantly (instead of 100% to 70% in less then 1300 miles, now it moved barley if any after a couple hundred miles) and I'm happy, so far so good. Also dealer isn't always the best option...

p.s only cost me 70$

 

I was waiting for the punch line...
Sorry bud, your dealership is just making money off you.

Having read these forums for years, the two most common reasons for an oil leak (oil leak was never specified in the OP) are the oil hoses between the oil cooler and filter housing and the cam phasing solenoid seals. Either one should be simple to identify. Its simple enough to get it hot and follow the smoke trail.
Anyway, your stealership is playing you. Mechanics are not that stupid, not even the new ones.

As for your statement about the heater not working because of oil in the coolant, no, that won't make your heater stop working, that will make your engine stop working.
Do you examine the coolant for oil and the oil for coolant? are you seeing any signs of contamination in either?

Your water pump has a weep hole for coolant to escape. Any signs of that?
Your hoses were replaced so your system was refilled. these trucks are difficult to burp. You may have an air pocket in the heater core. My truck ran for thousands of miles with air pockets from the original fill that I wasn't aware of until I gunned it one day, to find my reservoir almost empty the following day. It wasn't a leak, it was an air purge.

Anyway, find an independent mechanic, hungry for business, you can build a relationship with. He will charge you high on some things and low on others, thats the business. But he's usually much more honest than the stealerships. Smarter too.

 

I was waiting for the punch line...
Sorry bud, your dealership is just making money off you.

Having read these forums for years, the two most common reasons for an oil leak (oil leak was never specified in the OP) are the oil hoses between the oil cooler and filter housing and the cam phasing solenoid seals. Either one should be simple to identify. Its simple enough to get it hot and follow the smoke trail.
Anyway, your stealership is playing you. Mechanics are not that stupid, not even the new ones.

As for your statement about the heater not working because of oil in the coolant, no, that won't make your heater stop working, that will make your engine stop working.
Do you examine the coolant for oil and the oil for coolant? are you seeing any signs of contamination in either?

Your water pump has a weep hole for coolant to escape. Any signs of that?
Your hoses were replaced so your system was refilled. these trucks are difficult to burp. You may have an air pocket in the heater core. My truck ran for thousands of miles with air pockets from the original fill that I wasn't aware of until I gunned it one day, to find my reservoir almost empty the following day. It wasn't a leak, it was an air purge.

Anyway, find an independent mechanic, hungry for business, you can build a relationship with. He will charge you high on some things and low on others, thats the business. But he's usually much more honest than the stealerships. Smarter too.

^ This, and call your CC company and dispute the charges for the previous two repairs that did not fix the issue.