Oakhurst pay back my excess fee and fix my windscreen

Desperately looking for help as I am getting no joy from Oakhurst. I got involved in an accident on the 21 of February 2018. I submitted my claim with Oakhurst, getting my car fixed was a mission on it’s own. Long story short, I was told to go fetch my car at the panel beater. Everything else was ok except for the rear windscreen. They had installed an old windscreen full of scratches, way older that my original windscreen. I reported that. they ordered another one, this time the one they ordered was just a funny glass with bumps and very uneven to a point that the back wiper couldn’t slide smoothly on the window/glass because of the bumps. They told me they will replace the windscreen. After I had waited for months I am told to pay excess if I need it fixed when initially it was not done properly by them. They just refuse to take ownership and each time I call for help I am sent to a different consultant who knows nothing about my query. As if that was not enough I am still awaiting for my excess to be recovered from the third party, third party has insurance and they had assured me they will fix my car through their insurance but my insurance is playing hide and seek. I want to believe third party has paid for the damages but my insurance just refuses to pay me back my excess fee because they are ******.