Worst Response time and they just redeem your voucher even after being told you are not able to make the appointment

Bought a wikideals lash extension voucher which was only valid for 3 weeks. Wikideals extended the voucher but I couldn't get them to change the date on the voucher. I sent coco vogue the extension email that I received via WhatsApp and asked for a booking. They took their time to get back and I couldn't apply for leave on short notice. Coco vogue went and redeemed the voucher without me even confirming the appointment. I am now struggling to get a refund from Wikideals as the voucher was apparently used.