Select Surfaces

Select Surfaces installed Cambria countertops in our house on 7/24/2017. The installation was done incorrectly causing multiple alignment and overhang issues. There were two main areas of concern: 1) Window wall & 2) Kitchen island.
Select agreed to correct both issues and quoted us $504 to reinstall the window wall countertop because that incorrect installation was related to misalignment of cabinetry by another contractor. They agreed to correct the kitchen island free of charge as that was entirely due to incorrect installation by Select Surfaces. On 4/16/18 Select came back to remove and reinstall countertops and backsplash. After the installers left, we noticed that portion of the backsplash on the window wall side popped off or causing a sharp reveal and creating a safety hazard. Additionally, different color caulking was used during reinstallation and original caulking wasn't removed causing discoloration and poor bonding. Within a few days the caulking peeled off creating gaps.
We emailed them as soon as we noticed these issues & they promised to come back to address them. However no attempt was made to schedule a repeat visit, and our email inquiries and reminders went unanswered. On 6/12/18 we received an invoice for $504 from via email. We responded reminding that we were still waiting for them to come back to fix the sharp edge and caulking issues. Again, they replied that they would come over but no scheduling options were given to us. Again, I sent multiple emails between June & December '18 asking for a date and there was no response. On 12/12/18 we received a threat that our bill would be sent to collections. Since then, I've tried to contact the company and schedule a time for them to come. I've tried to contact the company and schedule a time for them to come back multiple times and they're ignoring my requests. Meanwhile, the exposed sharp edge has already caused multiple injuries.