False advertising!

I ordered a LARGE size thermal t-shirt that fit's my 8 year old but definately NOT ME.<br> I immediatley contacted Groupon to return the product. It has been weeks later and now only do they tell me I can't return it because it is openend! How am I suppose to fit it if I can't open it?? The package it came in is in EXACTLY the same condition?? So I paid R300 for a product I can't use???<br> <br> <br> <br>