Bad service

I called med-scheme on 28/12/2015 and spoke to an agent called LINDA WILLIAMS, I have spoken to many agents in the last 2 weeks and all promised to call me back with regards to my query non did so when she asked if I would like to get a sms or call back on the same day I told her to please call me.<br> <br> Two days later and still no call, I called in today and spoke to a different agent and asked her to speak to Linda. She told me she was on a call and asked me if she can assist me. I told her I am upset because Linda said she would call me and she didn't and I am still waiting on feedback. She put me on hold and spoke to Linda who told her she did call me on both phones (mobile and work) but I didn't answer and sent me an email. I told her to hold on and logged in to my account and told her yeah fine its here but still so many agents said they will call me back and non did so I'm very upset with the service and also the email correspondence I get from Med-scheme as it is badly worded and also sometimes has spelling errors. So LINDA just called me at work and shouted at me and told me I am ungrateful and slammed the phoned down in my ear. This it the worst any agent has ever treated me!