Xfinity Chat asked for IMEI, Phone #, and sent iGuard link for SSN & DOB

Hi there, 

I opened an Xfinity chat via the official Xfinity website to ask about a current BOGO mobile line promo. The chat seemed normal enough ; after confirming the promo was valid for my scenario, the chat agent said he could go ahead and get this taken care of for me and to ensure I received all available promos & discounts. He then asked for the IMEI and phone #s associated with the devices I wanted to bring to Xfinity Mobile and sent an iGuard link to capture my SSN & DOB. I was suspicious of the link but after opepning it, it had my full name, address, and Xfinity account listed, and the site certificate came up as valid and secure. I provided the information requested and then the chat agent stopped responding to my messages. I then got a vm from [Edited: "Phone Number":]  ; a few minutes later I got 2 Xfinity secure codes via text message that I did NOT request. I got a terrible feeling in the pit of my stomach and felt like I had possibly been scammed. 

I then immediately called 1-800-Xfinity and received a link to chat with an Xfinity agent via SMS text. He confirmed some of the information I provided to the chat agent but then continued to give me the hard sell about opening the accounts. I know that scammers are very savvy these days and still fear that my SIM card could have been compromised after providing my IMEI and phone #s and am worried I got myself mixed up in some elaborate phishing scam. Is there anyone who can verify if the SSN & DOB request was legit or if I need to start totally freaking out? Thanks in advance!