Boostgram is an unethical firm. I tried to unsubscribe months ago, they claimed to have no record, and continued to charge me. Additionally, they purposely hide the unsubscribe URLS from their main U/I so it is extremely difficult to cancel your subscription. Then, when I sent a follow-up email, my client rep Grace pointed me to their FAQ where they "clearly state you must email in order for a rep to send an unsubscribe URL". What a HOAX! Boostgram also gets your account flagged by Facebook for unnatural behaviour and reduces your reach and engagement per post. DO NOT USE THIS SERVICE!
I still haven't received a refund for their horrible service. This is my first time giving a review of any service, but I don't want other users to experience the same. Do yourself a favor... move on without them.