If your service is not a scam, and your telegram account has never taken money or other items away from a person, your tag will be removed quite easily. Even if chats are deleted on both ends, the scam tag will still come out if people have reported you enough, and telegram will personally go through your olds, I believe.

It's nothing big for you to worry about - a lot of reputable accounts have been spam reported, and the telegram scam service is still very new, pretty sure if you get scam reported 5+ times, telegram automatically gives you the scam tag, and you need to contact their bot, or their support. Fairly easy to clear up.

Good luck with support mate, it should be pretty simple.