Panel beater paid but did not deliver

i paid jetmatch to do panel beating on my car fron bumper,we agreed on the price and i paid ammount in full,they came with mobile truck to my work to fix the bumber but they didnt manage,6 months later my front bumber peels,martin doesnt want to take the blame as he told me he sold the business,i was given 1 year guarantee and its still less than a year and the poor quality work shows from my car,please fix this issue.