did they ask you to sign any paperwork at the time?
OK. Are you asking what will happen?
Well, it depends how much risk you are prepared to take.
On the face of it, it is a fairly safe action to refuse because they don't have the drugs so cant analyse them.
if they can't analyse them then it is not possible to prove that it was prohibited.
Obviously you are running the risk they cannot prove this.
Can I clarify anything for you?