No, Trump did not run on promising to take away millions of people's health insurance, raising the premiums and blowing up the insurance market. What Trump promised was:
On 60 Minutes in September of 2015, Trump vowed that everyone would be covered if he won. “I am going to take care of everybody. I don’t care if it costs me votes or not. Everybody’s going to be taken care of much better than they’re taken care of now.”
"Obamacare. We're going to repeal it, we're going to replace it, get something great. Repeal it, replace it, get something great!"
Trump reiterated his pledge that every American would get coverage at a February 2016 MSNBC
town hall. “We’re going to take care of them. We’re going to take care of them. We have to take care of them. Now, that’s not single payer. That’s not anything. That’s just human decency.”
“You will end up with great health care for a fraction of the price and that will take place immediately after we go in. Immediately! Fast! Quick!” he told supporters at a Las Vegas rally
that month.
“We’re going to have insurance for everybody,” “There was a philosophy in some circles that if you can’t pay for it, you don’t get it. That’s not going to happen with us."
“I was the first & only potential GOP candidate to state there will be no cuts to Social Security, Medicare & Medicaid”
As for the excuse, yes excuse, that the payments are illegal, instead of going to Congress and asking for an appropriation, he decided to up-end the insurance marketplace.