Follow/unfollow questions

I already have a instagram account which has 5k+ followers. Getting 20 followers naturally everyday but still using follow unfollow method

Question:
How do you avoid following the same account you follow before?(i can't still bought followliker)
Do the unfollow limit on crowdfire are the same when you unfollow manually(unfollowing 800-1000 on manual method) . I tried using instafollow but when my unfollow reach 300 i got temporary bans.

Thanks