Very poor service

I bought my Mitsubishi ASX from We Sell Cars in August 2017, that whole experience was very disappointing, the one Sales person was very rude that helped me in the place of the original sales person who was off sick. Eventually the purchase was finalised and I got my car, they day after I got my car it died, we then realised that the original battery of the car wasn't there and the fitting that goes onto the battery was way to big for the small one that was in the car. Putting that all aside in end of September I mailed the Sales consultant to follow up on my registration and number plates, where he let me know they didn't accept my proof of address, why didn't he give me this feedback earlier? Fine I sent the new proof of address and a few weeks later followed up again as I am not receiving feedback, he then gave me a number for the place that does the registration, I called the lady only to find out they never received my proof of address, which was end of October, I then sent it through to them, the lady let me know that hey will give me feedback once done. Today I sent an email again and the lady phones and told me that the car needs to go for Roadworthy, the car went in August already and the sales consultant I dealt with told her that he did let me know the car needs to go for roadworthy which he never did, this is VERY INCONVENIENT!! my experience with this place was the worst ever, I wont recommend anyone to go buy a car at We Sell Cars with their level of professionalism and customer service being so poor.