Mango – Uncollected return, zero communication for 3+ weeks

I ordered from Mango and the item took roughly 3 weeks to arrive, with no updates in the meantime. Once I received it, I logged a return within 5 days as it didn’t fit. The return was confirmed as successful, and I was sent a return form with a promise that someone would collect the item within 3 days. That was over 3 weeks ago. No one has come to collect the package, and I have had zero response through any Mango channel: two support tickets logged on their website went unanswered, their customer service phone line does not work, and I have not been able to reach a single person about this. I simply want my item collected and my refund processed, as I was promised when the return was confirmed successful. It is extremely frustrating to have no way to contact a real person at a company this size. Order number: [order number] Has anyone else experienced this with Mango? Would appreciate any advice on how to get this actioned.