Very poor customer service

Sometime early in February I app**** for a credit limit increase on the Discovery App. A day later the App requested further documentation which I then tried to upload. I couldn't do so due to app issues. I contacted the 08000 number provided and a banker said I should wait until the next day for the system to be working. Since then, I've probably spoken to a dozen bankers who keep on telling me someone would contact me the following day. This has been going on for more than a month. It then got escalated to a manager and the manager was meant to call me back with feedback on my request. To this day, nobody has called me back. All they say is sorry for the inconvenience and frustration caused. The level of service and follow up has been a terrible experience. It would be fine if the application was declined. But at least notify me of this than send me on a roller coaster ride for over a month. Very very poor service