Early Termination fee

Last year, around August, I had requested Dish Network send me a plain receiver because I never use the DVR and fell I didn't need to be paying for something I never used.  They sent me a receiver and I returned the DVR receiver.  Now I want to cancel our service as we hardly watch tv anymore and the price of $36.99 was just a waste of our income.  I was never told that there was going to be a new contract with the downgrading of equipment at the time of the transaction but now they are telling me that I would owe them a $360.00 early termination fee.  I looked at their so called agreement and nowhere on it can I find any mention of a new contract being entered when downgrading equipment.

I did finally get them to just give us the introductory package for $19.99 and specified that it be locked in for the remaining 18 months but after looking at the contract and not finding any mention of what I mentioned above I just want out now.  We have been customers for 13 years and I find this type of customer service repulsive.