My one and only experience of YouFirst was in May 2020 when my reward booking in First was cancelled due to Covid. I phoned and got through very quickly to a friendly agent who advised me of my rebooking options, none of which worked for me so I went for a refund of the Avios and return of my companion voucher which was swiftly done and back in my BAEC account before the end of the call. The cash refund to my Amex only took two days.