are you out of contract? if so then get yourself on a new deal with new equipment. if you are in contract then call in anyway and tell them your wireless speeds are bad and you cannot have 2.4GHz and 5GHz running at the same time on the top broadband tier they offer which is pathetic really even if you have only 1 device able to connect at 5GHz and above. having said that before doing so what are your connection stats like? printscreen and post these if you don't know...
downstream
http://192.168.100.1/cgi-bin/VmRoute...wnstreamCfgCgi
upstream
http://192.168.100.1/cgi-bin/VmRoute...UpstreamCfgCgi