Can i say this message to abra support ?

If it's really problematic, you can always point them towards this thread... It should explain everything that needs to be said:

Abra wallet is using their (bittrex's) api to create new deposit addresses (and probably to process withdrawals aswell).
You used Abra's wallet and created a new BSV deposit address.
You sent BTC to this BSV address
If they (bittrex) import the private key that was used to generate the BSV address into a BTC wallet, they'll be able to give you a partial refund (it would be acceptable if they charged you a couple hundred bucks to pay their engineer to perform these steps).

So, you'll basically need Abra to confirm that the BSV deposit address created with their api was shown to you so you could deposit BSV, then you'll need bittrex's staff to send you your funds back.

To be honest, i have no idear if abra is going to be willing to acknowledge this to bittrex, nor do i know if bittrex would be willing to export private keys from a BSV node and import them into a BTC node. Some exchanges do this for free, others charge a nominal fee, some won't help you at all... It's a roll of the dice, but if i were faced with this situation, at least i'd try to get my funds back.