sterns does not deliver

I took my engagement ring into sterns Westgate mall to have it made smaller to fit my finger, being a happily engaged couple we asked the question as how long the process would take? The shop assistant said that it would not have taken longer than a week and that she would call me back for a quote as soon as possible. 2 days after I called in (myself) to find out more or less what would the cost be? The same assistant that helped me answered the phone and said that she would call me back within in 5mins without even taking my name or cellphone number over the phone call. Just before she hanged up I gave her my surname. Two days after that I was still waiting on their call I eventually went into the shop myself to try and find out what's happening they told me that my ring was delivered to the incorrect store even though they signed for it. I do understand that people can make mistakes but the fact that I spoke nicely to the consultant and both consultants got very irritated with me. The only reason why I was upset is because they did not call me back I had to go myself trice back to the store which is unacceptable as I am wasting my time off from work and my petrol money.