pathetic service with finance, incorrect debit amounts for 4months now. no feedback/solution

I joined the insurance 4 months ago but ever since it has been hell. -Prorata charged and not supposed to -Different debit order date ever since the policy started and gets blamed on the system upgrades. -Debit order date changed and amount without my concern after fixing it on the 7th Nov, again blamed on the system upgrade. -Finance dept dogging my calls and promising to call me back but they dont, -Put on hold when i call and after that i still dont get a solution -Quick to debit but cant solve a damn query that has been going on for much and yet they say they give us a peace of mind but instead they give us HEADACHE.