Duplicate account and Download speed bottleneck

I have two problems that need to be fixed.

1. This week I upgraded from 1.3 -> 2 gig internet and somehow a new account was created for this service that is the same as my the existing one but missing the apartment number (Apt 3.) I need to only have one account open and I do not want to be double billed.

2. Before the upgrade my internet was being capped at 300mbps even though I was subscribed to 1.3gbps, after upgrading to a new Arris S34 modem and 2gig the internet download speeds from my router (this is tested via the RoG GT-AX11000 router web interface with nothing in between it and the Arris modem) is still capped at 500mbps instead of 2gig. The wifi router has a 2.5gig port as does the Arris modem. I am seeing the correct increased upload speeds ~300mbps. I need someone to fix whatever the problem is on your end to unlock the correct download speeds.