Mass Instagram account proxies?

I've been using a tool called InstagramBuddy to create mass instagram accounts, but having some issues. I obtained proxies from this forums proxy list and scanned them and removed any invalid or open proxys. I created 100 accounts, 1 account per proxy, with 3 second delay. Most of them got deleted except for 15 or 20. Why is this? Any help would be appreciated. Thank you

create accounts using premium proxy, i mean buy private proxies...

I can recommend HMA (HideMyASS) premium proxies, or google for dedicated private proxies, they aren't getting blacklisted in contrast to public proxies.

best regards

Instagram Proxy is a free service which enables you to bypass network and firewall restrictions and unblock instagram along with other popular websites.

Because the proxies/ip you used was flagged. Simple as that.