The telephone number +1855-298-2507 has published in social media posts, blogs and articles all over the internet as an Instagram Customer Support number. You will see other online users claiming that they received a lot of help after calling 1855 298 2507, the fake Instagram customer support number. This was done to convince and trick online users into calling the fake number.
If you call a so-called Instagram or social media customer support number and you asked to for your account credentials, it is a scam. And, if you have already called a fake customer service telephone and you were asked for your account credentials, please change your password immediately before your account is hijacked and used fraudulently.
I have seen a lot of innocent social media users who have gotten their account banned or suspended because their accounts were used fraudulently without their knowledge. They are tricked into giving out their account credentials over the phone or were asked to visit phishing websites that steal account credentials.