Worst customer service I have experienced

On 13 November I emailed documents to amend my surname and contact number. Today is 05 December, I have called in twice to date my details has not been updated. I was told today my email has been looked at! no action taken, now I am told to provide additional info. In the almost 4 weeks that has gone by I received no feedback, I have to constantly call to follow-up for them to do their job, worst thing is this is causing a delay as I want to sell my shares but cannot if my details is not updated. In this day and age where TCF is a major concern I have to say this client has not been treated fairly!!