My problem is I need metric alloy bar, which is not that easy to get, so I usually order from AW long enough in advance to give them a chance to get it in. However this time they've substituted it despite being told not to, and are doing nothing to fix it.

I have however just found a feefo feedback request for them, which has just been completed.
If there's no response, I'll get onto the bank next week and get the chargeback process started, as I'm not going to lose out due to their incompetence.