Slow to pay consignee and unresponsive

Very slow to pay me as a consignee (still waiting). The Changing Room took 2 items on consignment in March. I wasn't informed when the items sold, but happened to check their website in early June to see that they had in fact been sold. I e-mailed the store, who confirmed on 11 June that payment would be made at the end of June. I am still waiting to be paid (mid-August) and the three e-mails I have sent to follow-up have been ignored.