First of all we do not sell cc or dumps nor we have a shop, we just offer checker services to check card validity.
Balance Checker can flag your card sometimes as some banks dont like pre-auth, all depends on the bank.
CC/DUMPS Checker works perfectly and does not kill since it does 0$ pre-auth, so its impossible it flag your card, so if you want to stay safe from flags, use CC/DUMPS Checker wich is very accurate, if you card didnt work there may be another reason for sure.
http://luxchecker.pm/
http://luxchecker.pw/
CC/DUMPS/BALANCE Checker.