Welcome to the Community Forums @Fang128.
There are many topics and tips regarding better sales. Take a look around and joing the conversations.
To be honest, you post here wasn't very clear to me. Is someone responding to your ad, or not responding to your ad?
Not easy trying to do business over a **bleep** phone with small screen!
You can use a large Android tablet or even use the app from your PC with Bluestacks (free) as an emulator. It certainly makes buying an easier process on a 4k 27" monitor.