What happens when you click on Contact Seller?
I must admit the process is not very clear!
There's a Contact Seller link bottom left to click on again, then a large pop up box appears on the right. Do Not write in that box but at the bottom slightly greyed out is... Send Message. Click on that.
Write your message there, then a bright blue box appears..... Send Message, click on that.
The above is for when using a laptop / PC I don't use the app sorry, use Chrome too, that works well with eBay.
Be aware, some sellers can block you from sending messages.
What is it you are trying to ask? If for a refund , then no message is necessary if in time just open the relevant case.
Come back here if you need help with opening any case.
@azokha0
