Sterns *********** and unempathetic

So I bought an engagement ring from Sterns on 4 September 2017 and the salesperson did not tell me the ring cannot be resized. No problem then until we go choose another ring at the Somerset West branch and had it sent away for resizing. When we collected it on Thursday 14 September 2017 the ring had been sized to L instead of I [for idiots in this case]. Now the issue is we have had to postpone our engagement party after the first debacle and probably have to do it again because Sterns cannot service their clients correctly. I would have expected that they accommodate us and find a supplier that could resize the ring correctly so we do not have to cancel out engagement party AGAIN, HAVE A BIT OF EMPATHY. And to top it all we will probably have to pay for the resizing twice. I feel I just have to cancel this deal and then they have a ring that they cannot sell that is worth a few thousand rand, then get a ring from another retailer because we will in any case have to reschedule the party so we might as well wait for another ring.