Shipping/msg advice

I dropped off a package in the usps bin without checking it in bc it was my first time using depop shipping and I thought bc it was prepaid i wouldn’t have to. Now it’s been 4 days and depop says it still hasn’t been shipped. I’m going to call later today to get it sorted out, but in the meantime does this msg make sense/how would you make this right for the buyer. To me this seems fair but i also haven’t been on depop for very long so idk if this is a normal response.