Rather than asking the company to cancel subscription remove there source of payment. If payment by credit card: Tell credit card company your card is lost and ask for new one. The new account number should stop renewal. Using a checking account: Ask bank for assistance. Good Luck!

Hey, Be careful of "Jim K,'s answer. He sounds like an EHarmony employee. The vast number of complaints make his response ring hollow. I will again detail my experience. They effectively stole $100's from me...
You just got an E-Harmony response. Believe me, it is NOT easy to cancel. They stole $100's of dollars from me. How?
1. Never providing either email or paper receipts of their month
2. Never informing me of the huge per-month charge increase
3. I tried cancelling ahead of time and the phone people had this crazy answer about having to cancel only within a two-day period once every sixe months.
IN SHORT, they did everything to steal money from their clients.
Oh, sure, they could refer to fine print in the contract, but that only came out after the intro deals quietly expired (once again, they provided NO notification that rate just went up by 3x).
They are a predatory company. Never date anyone from EHarmoniy... you will be abused!

You can easily set up "Do Not Renew". Just go to Accounts then Billing. It's fairly easy but if you're having trouble, call 1-800-803-8931 & have a rep talk you through the procedure.