Not to sound mean, but you will find no sympathy here. Competitive matches to most players are taken very seriously. You should not attempt to start a Competitive Match unless you can 100% make sure that you will not be disturbed during the course of that match.
Also note, if you are completely banned from Competitive Play for the season, then that means you have had multiple leaver violations already. If you have been dropping matches due to a faulty connection, you must take every effort to correct any technical issues. You are responsible for your own equipment and the ISP that provides your internet when it comes to technical issues with Overwatch. Learn more about this policy here:
If you need assistance with troubleshooting your internet connection, players like myself and Blizzard can provide advice in the technical support forum.