I want to switch my cell phone plan

My plan is over $150 per month. I have 2 phones because I pay for my niece to have a phone. We both have unlimited everything although our data gets throttled because we go over 2G of data per month. I barely go over 2G but my niece uses over 5G per month.

Now I want to switch to a value plan where you pay for the service but there is no subside for phones. Either you can pay full price for a phone from the company or bring your own phone. The problem is that they don't want to let me get the cheapest plan because of the data. I'm also getting the runaround on whether or not I get to keep my corporate discount.

I'll have to crunch the numbers before I commit and change anything.