employer seeks repayment...help!!

[jadopheide]

I was a sales rep. for a company and they gave me an advance on comissions. however, my actual sales came in lower than projected. I never to my knowledge signed any documentation stating that I would repay the amount should this happen. I no longer work for the company and the company is now seeking repayment and I dont know if I'm legally required to do so.

Any help?????