Who protect the sellers?

[yan07340]

I have a problem with a buyer who asks me 5 videos testimony in French, the price is normally 80dollars and 3 days for delivering , but I offered him an offer to 60 dollars, but it requires 50dollars after having ordered my gig, so I try to cancel the order but he refused without explanation, I try to have a new communication and the buyer told me he wants everything in one day (so extrafast)so he want an work of 150dollars but paid 50 dollars, I do it because I’m afraid that poor assessment destroy my 100% positive rating … now this buyer have 25 very good videos by the requirement because I always send several videos to give the choice the buyer, and he told me … I’m waiting for my upper gives the agreement for your work … at no time I read thank you, who protect sellers??what can i do??