Second post

Hope it's correct section.
Situation description:
I'm member of specific forum which apart from other activities offers commissionable services. Forum has it's own rules yet each commissioner has it's thread with time frame of their service, price and other data.
When person (commissioner) is ready to take commission from other members he/she opens slots and accepts reservations. Usually around 10-20 people in one batch.
Once you're included on waiting list when it's your turn to be served you pay in advance and send PM to commissioner how you want the service to be done plus you send him item on which this service is supposed to be given.
Commissioner is more like artist.
So there are delays sometimes because of lack of motivation/creativity.
*edit*
Oh and most of them usually gives their service in their free time as part of their hobby.
Anyways..
My situation:
I've received such slot around September 07'.
My turn was around end of November so item was sent and commission was paid on 29th of November.
Artist (commissioner) maximum time frame was 8 weeks.
I've waited till last week (around 16 weeks after payment was made and 8 weeks over artists maximum time frame)
I've contacted commissioner several times during this period and always received some kind of excuses, why work has not been done yet.
Apart from last one when main tool needed for such service was supposed to be broken all other were lack of motivation/lack of internet or no excuse given apart from "I'm sorry for delay".
Last week after I've contacted commissioner and asked about progress I've received same response with refund offer if I don't want to wait any longer.
I've written to commissioner expressing my concerns about waiting time and I clearly opted against any refund.
Commissioner replied that service won't be done since I dared to point out few facts against refund (dollar value drop - so refund of exact sum was a loss for me - apart from fact that Paypal payment can be refunded up to 2 months so after that it's payment not refund, my waisted time and possible devaluation of item for which I've paid in dollars - for obvious reasons is worth less now) And demanded my Paypal address for refund and my home address to send the item back without completing (or even starting) service that was supposed to be done.
Due to forum rules such situation is possible if client is problematic or service can't be done properly.. But those rules have been bended to fit commissioners want-to-do-so-I-will attitude.
I would like to ask if there are any consumer rights that would suit this situation? After all service was paid so that's kind of agreement.
At least I think so.
I would be grateful for advice.