Silkies ripoff, received bill after receiving a free pair of silkies and bill had no phone number Philadelphia PA

I received an advertisement stating if I sent in the notice I would receive a free pair of pantyhose. I went ahead and sent it in, then I received the panties. About 2 months later (yesterday) I received a bill for $13.93 stating it was passed due. I tried to call Silkies immediately, but to my surprise, ther was no phone number listed on the bill. The next morning I looked up their website and found a phone number for costumer service. I called and was able to cancel the bill. They explained to me that the free pair advertisement indicated that there would be a monthly shipment of hosiery and if the person didn't want it they could sent it back. I don't recall seeing it and I never received another pair other than the free one. Silkies customer service canceled the bill for me.

Ruby
tracy, California
U.S.A.