Opting out of Lifetime Membership

At this point this is just a hypothetical question but would there be any way to back out of the Lifetime Membership I upgraded to just prior to SoM coming out? I upgraded because I was happy enough with the prior expansions and optimistic about Mirkwood.

I HATE this expansion. I find I loathe the skirmishing, the quest structures, mobs like the bog worms ... I can't say I've found anything I like about it (which is rare). At this point I've paid more than twice what it would have cost me to just stay monthly and find out how much I dislike Mirkwood. Four times as much if you count the fact that I took the summer off and therefore didn't play for three months (I would have suspended the account and not paid anything during those months).

I know, I'm in the vast minority in how I feel about Mirkwood. I'm not asking them to pull it out, I'm asking about an option so I paid the regular quarterly rate I was on before for the four actual months played since I upgraded rather than end up paying $40-50 a month for them should I decide to cancel.