Parmjit Kaur, 32, was spotted throwing the butt to the floor outside a shop called Savers on Gillingham High Street in January.
When a council community officer approached and said it was an offence to throw litter, Kaur replied that she didn’t realise. But the officer showed her a sign on the street stating this that was just yards away.
Kaur, of St Alban's Close, Gillingham, was issued a fixed penalty notice for £80 (which is reduced to £60 if paid within 10 days).
However, no payment was ever received and the case was referred to the council's enforcement team who asked Kaur to attend an interview.
When Kaur did not reply, she was summonsed to appear before Medway Magistrates Court, but failed to attend and the case was heard in her absence.
After hearing the evidence, the bench found Kaur guilty of littering and handed her a fine, to be paid within 14 days.
Passing sentence, the chair of the magistrate’s bench Colin Smith said: "The defendant had the opportunity to pay £80, which could have been reduced to £60 had she taken prompt action.
“I am therefore going to add £60 to the fine, making it £140, plus a £15 victim surcharge. It has also cost money to bring this case to court and I see no reason why Mrs Kaur shouldn't pay the full costs of £262.91.
“This makes a total of £417.91 and I hope this sends out a message to all others who commit this very anti-social act."
Following the hearing, which took place on 31 July, Cllr Mike O’Brien, the Portfolio Holder for Community Safety and Customer Contact, said: “The council works very hard to keep Medway clean and it costs nearly £3million of public money a year clearing away after those that litter.
“Littering in public places is anti-social and shows scant regard for others and we will always take action against anyone who we see doing this.
“In this case, this lady could have avoided prosecution and a larger fine for littering if she had paid the fixed penalty notice in the first place.
“I am pleased the court has recognised this and increased the fine as well as stated that she must pay for the cost to the taxpayer of bringing this case to court.”