So, Cathy-Ann is your first name, and Ann is not a middle or second name? This is what they probably assumed. Normally a shortened name is not a problem, esp. if it's really long (they go mostly by your passport), but in this case if it's your entire first name, then I'm not sure. I don't think it will really be a problem, but it's worth looking into.
Yeah, USCIS. I call it CIS because I feel the US part is really unnecessary, just like most of the US flags that are displayed in the country. We all know where we are . It's like how they always have to say "the president of the United States' every freaking time they mention the president, even though most of the time the context makes it quite clear about which president one is speaking. Should we call it USDoS for the state department, and the USNSA for the national security agency? We also do this for USPS and law enforcement agencies, and I'm annoyed.