SHOCKING SERVCE TO A LONG STANDNG CUSTOMER OF THIRTY YEARS.

Have been a customer for over 30 years. Was on the telephone with your customer care centre who kept me waiting for 25 minutes. to solve a simple issue.Whenwe. sent a letter of complaint with reference no. 216H4 I tried follow up this morning only to find out that there is no such reference number. Will someone please contact me urgently to resolve my issue as even my complaint per email is bogus. Thank you