below standard service

Ok so I collected my vehicle back , the 2 days after I picked up that there was sum problems so I phoned in , got told to speak to one on the managers , while holding the line was cut. Phoned in again and left 2 messages for them to contact me which they did not do , so I sent and email and got a reply 3 days after to bring in so that they can have a look which I did and was told they will give me a book in date to that the can resolve the issues . I sent 2 emails after that and no response either . Now it's more than a week later and I still have not received a date on which to bring my vehicle in and I need the issues to be sorted ASAP. I don't even know how this got past the quality control which was supposed to have been done.