“ Good afternoon,
We appreciate your response.
However, please note that accounts are clearly accessing from the same
geographical location and the betting pattern found confirms the fact
that accounts are close related.
We would appreciate if you could cooperate with this matter as having
more than one account goes against our policies.”
Kind of oddly worded lettering. Well, I would just "cooperate" with them like they ask. Tell them you've never multi-accounted and you don't plan to start now.
Tell them you believe they generated a false positive and to review their findings.
They've been in business for a long, long time, and for every complaint about them on the forum they've processed 100,000 bets without any problems. It's impossible to know if they are "selective scamming" or just wrong (or if you're lying), but the problem can be avoided by sticking with 1 IP address in the future (preferably your own).