There was once I bought a pair of TP-Link Powerline adapter from challenger. After trying out at home, I realised it had slow connection speed and went to exchange for Aztech. Then, again, I find Aztech one was even slower. So I went to challenger to exchange for voucher so that I could take my time to slowly research before deciding on which brand to buy. So I think there shouldn't have any problem for TS to get a credit refund. Challenger has the best customer service!