Spotify is not checking internet connection but rely on windows internal and bugged mechanism. It causes error code: 4 even if there is connection, and it is even more annoying when there is specific virtual switches configuration, making spotify unusable. FIX: Change it, so it pings your server or whatever else server to ensure if there is connection instead of trusting windows in that matter.
You are providing paid service that isn't working. This is base to get refund for all months when service wasn't working correctly when it should.