Size of text

I have many problems with the small size of text in chat rooms... I just cant see it and when I type it takes me longer and mistakes can occur in spelling.
I did try to enlarge using my pc tools but it only enlarges the rest of the site not the chat box text.
I have tried to explain to hosts but they just keep muting me and will not accept my using caps...
Any ideas as this cant be resolved ... I thought there was facilities for hard of hearing and sight probs on every website?
Cheers