Still waiting for my refund

I posted here nearly 4 weeks ago about an item I couldn't collect in time, that was returned to the seller but the seller denied they had received it.

Well I've waited for the requisite time, contacted Vinted again, and they have immediately suspended the order saying they have no evidence the item was returned. Now I have to wait for another 35 days before they will refund me.

I've never experienced this before - is it standard these days?