website access denial

I have my medication and health care providers sites preventing me from signing onto their sites. The 403 forbidden message is being displayed. Attempting to input ID and password pushes me to the notice that there is a problem with my website address and check the spelling. I have talked to the csvc people at the health care providers site and they tell me there is no problem at their end-they recognize me and have access to the site's information. Is there some action that I need to perform with the hotspot?