I just discovered the same charge on my credit card! Apparently, in the fine print on the agreement, when you sign up to get the "free" sample, you are also legally bound to receive their product EVERY month a the cost of $89.31, until such time as you contact them to cancel the contract.
Here is what I was advised by my credit card company (VISA) to do:
1. Attempt to contact IP-GREATONLINEDIET (877-361-8616) to cancel the agreement. Then, if they have sent you anything, you will most likely need to ask for a Return Number from the Returns Dept. in order to ship the item back to them, and get your money reimbursed on your credit card.
2. If you cannot get through to them (I couldn't even when I called during normal business hours) let your credit card company know you tried to cancel, and they can put a freeze on any further charges on your card by this company.
3. Keep trying until you get through to the company, and go through the hassle of returning the bottle and getting your money back for the ones they have already charged for.
4. DON'T just put Return to Sender - they will most likely not accept it this way (without an authorized Return number) and will not refund your money.
5. From now on... READ THE FINE PRINT!!! I know I will!
Hope this helps.