Poor After-Sales Service from Maxidor

Whilst the product (I have 20 installations in-home, including sliding gates and burglar proofing) has performed slightly "below satisfactory", the AFTER-SALES SERVICE experienced when trying to effect repairs has been appalling - Primarily, I cannot get Maxidor to honour their assurances/promises of a consultant calling me to even telephonically address the repair issues - 4 calls to Maxidor over 3 days - NIL Maxidor call-back or action!? Home security is at risk and Maxidor is absent in their response to their broken product.