When you upload a file to your nokia 3650 from the pc and it goes through the message folder does it use a text message? Like i only have 250 text messages a month and will uploading files count as one?

It lands in your inbox as a text message if you send using BT, but if you mean you can only recieve 250 a month due to your subscription?

Then the answer should be a no. It does not go through your provider and therefore they cannot count it