Cancellation

I received a call for an upgrade from 600gig to unlimited for the same amount and a home router. The router was delivered but only got 400gig instead of unlimited. Ive been calling since November asking them to collect the router and cancel or give me a better offer. It’s either they say they will follow up or they will escalate and get back to me. Otherwise im sure when i call again they’ll say they cant see anything about the call.