faulty R4 cards

Hi. ive been buying alot of R4 cards latley.yesterday i had 5 deliverd and 1 was faulty, they were from amazon.

today i had 4 deliverd and three were faulty.they were from ebid.
is anyone having this same problem with faulty R4 cards???

how do i go about getting a refund from an ebid seller?? as this is the first time ive used ebid?

i have contacted the seller and he said the cards were tested b4 he sent them out to me.he did then say to send them back for replacment.

but as i said b4 ive had quit a few faulty r4 cards delivered in 1 day