Having problems getting my Podcast onto I Tunes

Your image, which is at http://i1.sndcdn.com/avatars-000153023951-85x6n9-original.jpg , is 2452 x 2372 px and is too large. The recommended (and indeed the minimum acceptable) size is 1400 x 1400 with a maximum of 2400 x 2400 so you need to bring it down in size. It's preferable to make it square. There's no point in having it any larger - it won't ever display at that size. When you change it you should change the filename.

This isn't going to be the end of your problems. Your feed won't be accepted because the media file for the top episode (and presumably the others, but they only check the top one) forces a download when you enter the URL in a browser. This means that though it will work when subscribed in iTunes, the Store can't stream it and so you will be rejected. You need to set each file not to download. eiznem has posted the process:

https://discussions.apple.com/thread/6523821?answerId=26564459022#26564459022

Don't re-submit the feed until you have a) downloaded the image and confirmed its size, and b) entered the URL of your media file in a browser, preferably Safari if you are on a Mac, and confirmed that it plays in the browser, not downloads.

There is a bug in the submissions process which you may fall over, whereby you are told a feed has already been submitted even if it was subsequently rejected or removed. The workaround is to change the title slightly - you can change it back once accepted. If you can change the feed filename, and hence its URL, this is also a good idea, as is changing the URL in the 'link' tag (this can easily be changed back afterwards). For this reason you don't want to have to keep resubmitting it.