hi can anyone help with incorrect shipping choice

[sewingforsanity]

Hi, when I use the ebay listing service, everything is great until I get to the postage part. It wont give me the option to add or choose postage as a "letter" I post as a letter to keep the costs down but it will not let me choose this with the drop down menu. If I select the tough bag etc it lists the cost. Even if I select free post it still lists the cost and "tough bag" as delivery type. If I do this the buyer will be expecting a tough bag. I dont want to do the wrong thing but how can I  get around this?