Do not respond - Warranty work

Commisioned Master Paving PTA to do some paving work. Got a quotation and got the guys in to do the work. There were 3 bits of work done. Two sets of paving.. one set of laying and cementing a walkway. The paving bit was good quality work. The walkway work cement disintegrated within a month of completion. Contacted Master Paving PTA numerous times via telephone and email to arrange for assessors to come inspect the issue for repair under the 10yr warranty. Was promised countless times that assessors would come view. No one ever came. Last follow up done via mail and phone was april 2017. To date no response.