PayPal - Checking on a 16.00 credit was told would be applied to next order

I ordered a set of 4 2oz fuchsia pink containers back in December when I received them they were dirty and and a mildew smell to them I was really upset and waited a day to connect with seller, after connecting with seller, after the emails sent, I would think that she would step up and either send me another set or refund my money, while waiting to hear back I tried several different methods to try and get that smell out, after the 4th try, I just threw them in the trash, then after reaching out to a representative and explained my situation, stated new, how can they be new with dirt on them? And a mildew smell to them, I was very honest with the seller, she should have checked the condition of what she sent me, when she reached out, stated she would give me a full refund if I sent them back to her, I stated I threw them out because why would I want to keep something that had that smell to contaminate my other Tupperware in my cabinet, reached out again to representative, and after a long conversation, I stated why should I be the loser in this situation she sent me, not what was advertised on the sellers site, so the rep stated she would apply 16.00 to my next purchase made I would see it was I checked out, I have made several purchases since then and have not seen any money or credit applied to what I was currently purchasing, so when is that 16 dollars going to show up? That is very dishonest business practice and I am out 100% of that item, I have found that item in different colors (4) delivered to me clean and no odors, but still do not see a credit on any purchases made since or any credit for the amount of 16 dollars, I would like to speak to a representative about this issue.thank you Barbara Prince