Sterns Kimberly poor customer service, lies and *************

Kimberly Town Sterns. Very poor customer service. I bought a watch at Sterns at hammanskraal and I reduced it there. 3 days after that the watch fell and i managed to get the pin,I was already in Kimberly. I took it to Sterns in town at Kimberly for them to assist me. Unfortunately they lost the watch pin, I had to leave the watch with them and they say they will call me in 2days.its been over a week now and am standing here now currently and they don't want to help me anymore because I must have a receipt now for them to get me a new pin which they lost. The lady is been rude with me and asked me to leave. I dont know any way forward now because I left my watch there now Kindly assist me in this regard