Refund after money back guarantee

I bought a bicycle and had it delivered by courier. Unfortunately, my courier was unable to pick it up at the time we had originally agreed. We agreed to try again in 2 weeks. Unfortunately, the seller has not responded to my messages since then, so the courier was unable to pick it up this time either.
However, so much time has passed that the money-back guarantee has expired. Is there any way I can get my money back?