Bad service

I bought a watch at truworths only to find that it is not working. When I returned it I was told I must buy a battery and if it's still not working they can exchange...how can I buy a battery for a watch that I never used?? Does this mean you guys sell watches and the customers buys battries for themselves? I'm really dissapointed. R450.00 for the watch and I must buy battery out of my own pocket as well😏