Asking for full refund upon failing to fulfil obligations by a manufacturer

Hello,

I am looking for legal advice regarding the following case:

I ordered from a clothing manufacturer several custom-made items (T-shirts, sweaters, etc.). While customizing the items before production, I was offered different fabrics and ended up choosing one which was presented to me as 100% cotton.

The items were made and the manufacturer put labels on each and every piece indicating they are 100% cotton.

Recently, someone brought to my attention that these fabrics were not 100% cotton. I asked the manufacturer to provide a certificate saying that they are and he refused, coming up with some excuses.

So I paid for a test myself and the results showed that indeed these fabrics are not 100% cotton. This puts me in a very bad position as I plan to sell these items, which I can't do now as I will be lying to my clients.

What can/should I do now? Can I ask for a full refund?

Thank you very much for your support!