I used a virtual credit card number (set the limit and expiring after 1 month). I never gave them my correct phone number. When the subscription was almost over, I sent them an email and USPS letter stating I was not renewing the service and if the radio stayed active after my expiration date, I would consider that a free gift.

It stayed working for about 2 months while I got lots of emails asking for a new credit card number. Eventually the service was off. Now I'm getting offers to renew at the special discount again. I rarely used it so for me it's not worth it even at a discount.