Spree's thieving/********* policy

I purchased 2 t-shirts which were on sale paying with both cash and voucher. 1 t-shirt did not fit me properly. So I returned the t-shirt and requested for a larger size.<br> <br> I did not request a refund or credit or the like, I simply wanted a bigger size.<br> <br> Spree did not have the bigger size that I required. Therefore, according to Spree's policy (confirmed by 2 different call centre employees - 1 being a manager), Spree is entitled to keep my returned t-shirt and not credit the monetary value of the voucher to my Spree Account! What is the difference between Spree's policy and theft? <br> <br> Spree willingly accepted the returned item and willingly refused to credit my account to the value paid via the voucher. Both employees I spoke to said there is no difference and agreed that the policy is ********* if not *******. <br> <br> They kept on giving me a worthless argument that the voucher does not have any value and they cannot credit me to allow me to buy something else. Spree was unable to provide their side of the obligation which was to provide me with the larger size t-shirt and thus are entitled to keep both my goods and my money!<br> <br>