How long does it take a somewhat bad burn from a cigarette to heal?

[Amcbain1186]

I burned my shin pretty badly with a cigarette. It blistered to about the size of a dime. The blister popped and I bought it was starting to get infected because of redness around it so I put antibiotic ointment on it and the redness around went down. It eventually scabbed over with this very dark almost black scab with wrinkly bits on it. The scab has been there now for over a month and doesn’t look like it’s falling off anytime soon. Does anyone know if this is normal? I feel like a scab not falling off for over a month is a bit extreme and when I pull up on it it’s definitely no where near ready to come off.