Moved Service - Balance Transfer

I recently moved apartments and moved my xfinity internet service with me. I'm being charged the "balance" from the old apartment this month, even though I moved on the 1st. This makes my bill double what it usually is (paying almost the full cost for this month for the old apartment, where I no longer live, plus the full cost at the new apartment.)

How can I get the balance from the old apartment removed from my bill? I shouldn't have to puy for service at both apartments.