https://bitcointalksearch.org/topic/m.19252915
https://bitcointalksearch.org/topic/m.19250024
Although there are also other reasons on why viabtc doesn't accept a certain transaction
1) Too low fee: We only provide accelerator services for those with at least 0.0001BTC/KB transaction fees;
2) Node reboot: When a Bitcoin node is rebooted, synchronization of transaction data may be delayed. You can try again later;
3) Previous transaction unconfirmed. Your transaction can’t be confirmed if previous transactions connecting to yours are unconfirmed. You’ll need to wait till all previous transactions are confirmed first. You can also use our accelerator to help with that.
We can’t accelerate confirmation of “Double spent” transactions either.
There is still a chance if its number 3 as stated from above