Swiss International Airlines - Online date change downgraded me to y HELP

I Have a big problem.... waiting for supervisor in Fiji to call me back.
I have been recuperating in SFO after a back surgery near my residence
in CHAM CH on December 20th. I was ticketed in Z. outbound back to Zurich. I wanted to
extend my time here in SFO and found there was a way to do this without
calling a call center, thru an online process. I did this paid a 408.00 fee
with a credit card, but when I tried to check in on line I found myself in coach.
The rebooking tool booked me in B class. I do not remember a screen that asked me if I was ok with a coach seat. Although the surgery has went well, my swiss neuro surgeon was not advising flying soon soon after surgery. There
seems to be business seat availability, whats the chance they will try to
help me with this? I credit milesto United but have flown six international business
fare's in the last year and a half. I like the in air product, but have found them
quite rigid, almost anal in there rigidity on rule interpretation. This seems like
a programming glitch, my fingers are crossed but I am scared. ANY advice welcome

Supervisor called back. She admitted this change tool is not clear and can downgrade c/z/to B. States they have sent memo's to ZRH HQ. You have
to accept the change, then open the attachment on the email to see the potentially changed booking class. However they want to charge me 1100.00 on
friday or 1600.00 to place me back into C tomorrow, even though the booking was in C (Z) originally
. She said she would try to see if she could get them to sell me the Friday fare for the flight tomorrow, but she has to get approval. Be very careful
if you use this booking management tool. It looks like this is going to cost me
1100 dollars.

Is $1100 the fare difference between Z and C or between B and C (one-way)?

HTB.