That is very unfortunate. Which slimming center is it? I think the problem is the consultant herself. Probably there aren't any refund in the policy, or there is such policy but for extreme cases. In order to convince you, she make up a whole lot more story.

When she can't meet it, she simply cannot refund it because there is no such thing, like the 2x refund. That would mean she need to fork out herself. It's a pain when we met this kind of people. Her dishonesty may bring down the company reputation.

I suggest you complain nicely, to other branch, best to the manager. Tell him/her your problem and hope he/she could talked to that branch manager to resolve this issue. Consider this as good deeds so you can help others from getting the wrong treatment.