Vinted complaint: Lost parcel and Vinted will not refund

I used the shipping label provided by Vinted to send a parcel with Evri. I have the shipping receipt from Evri but the tracking is not updating and Vinted is saying it is not the right receipt but it definitely is. All the other parcels that I sent at the same time on this same receipt all tracked and were received fine. I marked the parcel as sent after the tracking did not update but the buyer did not receive the package and wanted to cancel the order. I asked Vinted for help but they did not support me so the order ended up being cancelled by the buyer. The parcel has been lost by Evri. Vinted will not refund me the money I have now lost after lack of support and proper help from them. Vinted will not let me make a complaint about this situation either and have shut down the conversation I opened with them. I am registered disabled and this situation is hard for me to deal with as I have done everything properly and don’t feel I am being treated fairly.