Postage refund for returned items.

I am a regular customer of a well known big tv shopping channel. I consider their postage to send items out is rather excessive compared to other companies...but don't get me started on that! My question is this - I have heard Martin say recently, and have since read on here that if you purchase on-line, you have 14 days to change your mind and return (at your expense) in this case you should expect to receive a full refund plus the cost of postage to you. If I order from the tv channel's website then return within 14 days, should I expect a full refund including postage? I have returned stuff in the past and have only received a refund of the item itself. To be honest, because they say you have 30 days to return I have usually left it til the last minute to return, but if they are obliged to refund postage for a return within 14 days then I would return more swiftly. Any guidance on this?