Very Upset customer

I bought a ring for my wife at sterns,i took out insurance. Some one just cancelled the insurance without my authorisation. I went in store to they gave me a number i phoned the number it required a extention nr. I went back the manger then told me they suppose to call from the store and log a call,she then logged a call for me. Only to find out my insurance was cancelled by one of the consultants but i never requested a cancelation ,infact i didnt even know about it. If i didnt go in store i was not gonna know. Its been 3weeks now im still waiting for feedback on the investigation. Who can assist on this one because if anything happens to my wife ring,who will then be held liable for this?