*****ing from their customers & bad service

In May 2018 I phoned the insurance to ask about a chip on my windscreen, will it affect my cash back bonus? I was told only if the windscreen gets replaced then it will affect my cash back bonus. Only a chip was fixed and I phoned them to double check that it did not affect my bonus. On the 25th April 2019 when I logged in on my policy I saw that my monthly installment went up and that my cash back bonus is only due in 2022. My cash back bonus is due June 2019. I phoned and ask the lady to have a look at my query, she asked me to hang on because her understanding is also that fixing the chip should not affect my cash back bonus but she just want to double check with her manager. She said that there is no manager at the moment which I understand because I phone after 17:00 but she will get a manager to phone me during the day on the 26 April 2019. I told her last year I was also promised that the manager will phone me but I had to phone them the next day. I also promised her that if nobody phones me today that I will lay a complaint. No one phoned me today.