Why can’t we purchase??

Hi

my company and I have been trying to purchase the hierarchy tree (5 creators, 100 users) for a few weeks now and we always get an odd authentification error after entering credit card details. we’ve tried so many different credit cards etc but to no avail. Our PA has also tried to contact your help desk but we have had no successful help. Before I put this on LinkedIn, please can you help us resolve the issue?

Thanks

Tanya