The domain of my website is blacklisted, where can I report a false positive?

[Formspark]

Hello,

One of the domains (submit-form.com) of my cloud form sevice (formspark.io) seems to have been blacklisted by BT.

Unfortunately, a small fraction of our users use this domain for malicious purposes, and for this reason, it seems that BT has blacklisted it.

The Formspark team is very responsive when it comes to takedown requests and proactively tries to detect harmful content.

What can be done to make sure the domain is removed from the blacklist?

Would it be possible to whitelist the domain in question?

Thanks in advance!

[-Richie-]

Both domains loaded fine for me, so it's not a BT ISP block or it wouldn't load for me in BT BB.

If you have contact with the BT customers unable to visit the domains, might be worth asking if they have any anti-virus/firewall software installed, maybe that is the block, alternativly ask if the have parental controls active (I don't).