We moved out at the end of September and received a bill from Swiss Caution in November. I knew it took a long time for rental agencies to take care of things like this, so I wasn't too surprised. A representative at Swiss Caution told me that we would have to pay for the next year if they did not receive the cancellation by December 31.
I spent 2 months hounding my previous landlord... seriously... daily calls and e-mails! The person I was working with at Swiss Caution was very helpful and even called the landlord for me to help expedite the process!
He FINALLY mailed the signed letter in on December 27th. Saved us from having to pay almost 500 CHF.
But, I was relentless. The landlord would have probably paid me 500 CHF just to leave him alone at that point! I will say that even though it would have been a PIA to pay that money, Swiss Caution was very straightforward with their policies from the beginning. Yes, buyer beware... but I don't think Swiss Caution is in the wrong.