No response or after-sales service

The BATH,BASIN,TOILET, CISTERN, 2*SOAP DISHES AND SHOWER TILES in our flat have been re-glazed by BATHROOM DOCTOR on 12/02/2013. They've provided a guarantee valid for 5 years (WT.# 22095). As from the 28th of May 2015, I have been in contact with their offices, trying to get someone to fix minor areas in the bath where the glazing needed to be touched up. I've also requested a bigger scratch to be repaired/quoted for if not covered by the guarantee. On 3 occasions, an actual appointment was made, but no-one showed up. On further telephonic discussions, I was promised that someone will get back to me, etc. On the 17th of June - almost a month later, I've lodged a formal complained via email. I've received no phone calls or feedback as yet. What is the point of a guarantee if it's not honoured or if no after sales service exist?