SIM won't work, carrier won't help (Bell Canada)

After hours scouring this forum and calling my service provider for help getting my Kompakt set-up, no luck. My carrier says they can’t do anything to enable me to be able to have custom APN settings - no unlocking, no switching to a plan that would enable it. I technically have a “corporate/business” account because I got the phone through a discount associated with my employer. I called the carrier, they told me to call the 3rd party vendor that the discount was associated with, I called them, they told me to call Bell. No one knows what I’m talking about. So now I’m looking at having to switch service providers. I wish I realized how difficult it was going to be before investing in this phone. Any advice for when I make the switch of provider to make this work? Carrier suggestions that will know what I’m talking about?