Battery not matching, return worked out.
I ordered a new battery for the German "Volkstablett" Trekstor Surftab Wintron 10.1 3G as the old one bulged up via newlaptopaccessory.com. The battery was offered as matching and compatible. It arrived very quickly, but when trying to put it into the tablet it turned out to be too large, although it was offered as compatible. I contacted the seller, who sent me a return label, which I used to return the battery, and after a second contact to request the refund this was processed as well. All in all a good experience for me, although I would rather have had a fitting battery, and I had to contact the seller a second time after tracking information showed me the battery was returned correctly some time ago to start the refund process.