Kate Carter manages the Market Café Longue and indoor market on Regent’s Street and was a contributor to the letter.
She told BBC Radio Bristol that she was “so despondent” reading messages from the public who do not want to visit Kingswood with the changes in place.
However, one local resident said he is not bothered by the charges.
“Everywhere else you go in the country you end up paying for parking in towns and villages so it’s inevitable,” he said.
“People have just got to put up with it.”
A spokesperson for South Gloucestershire Council, said: “We are sorry to learn that one of the traders from the indoor market on Kingswood High Street has decided to leave and wish them well for the future.
“There has been significant investment and improvement work into the High Street and Kings Chase over the past months, with more to come in the near future, and occupancy levels for the retail units remains high with the centre currently fully let.
“The impact of the new parking scheme will take some time to assess, and we will be monitoring it over the coming months and comparing it against the baseline that we have already taken.
“We have had to take this step to help us meet the budgetary challenges we are faced with to support all of our local communities, including through regeneration work, but also supporting those in the community who need us the most.”