Yes, I am making device payments, i got the s8 when it came out. And I'm paying for my tablet line which I never use.
That isn't a problem with the carrier or your bill.
How much is your PLAN? Your plan is data and line fee. That and taxes is all you need to pay if you buy phones like you did on Boost - full price. No option to add tablets either.
You over extended yourself buying stuff you now realize you don't need. You can get Verizon service at a lower cost if you pay off everything and use prepaid. 3 gigs $45 a month and still can use the better network.