Since there were numerous front page and popular deals for these products over the past year I thought this might be helpful to some.
Follow this link for the PowerLine Return Program form:
http://www.tplink.com/us/claim/
"TP-LINK USA has learned that some customers may be dissatisfied with the speed or performance of their TP-LINK USA AV500 PowerLine adapters…TP-LINK USA has instituted a TP-LINK AV500 PowerLine Satisfaction Guarantee program to offer all customers who have purchased one of the following TP-LINK AV500 PowerLine adapters the opportunity to obtain a full refund of the purchase price"
TL-PA511
TL-PA511KIT
TL-PA4010
TL-PA4010KIT
TL-WPA4220
TL-WPA4220KIT