Jbc roofing customer care problem

I had repairs done on my roof in July 2020 which was not successful. I have called them back 6 times to repair their repairs and my roof is still leaking. They do not answer their phones and take up to two weeks to repsond to an email. I have taken off from work on their insistance to meet them at my home for them to fix the mess they made and they simply don't arrive with no phone lines being answered.

I am at my wit's end as they seem to not care at all that they took my money. They say their work has a 3 year guarantee but what use is that if they don't bother coming to site.

Any help will be appreciated