Extremely bad service

Worst ever after sales service received. Bought my car in September 2022. From day 1 the check engine light came on. According to the Dekra report no issues except a chipped windscreen and rear tyre running smooth. Car wad "fixed" by a RMI approved dealer. Car was gone for 26 days. The problems picked up was an engine oil leak, cv joints needed replacement, o2 sensor needed to replaced and a gearbox oil leak. Had the car back for 2 days and check engine light back on again and now the car jerks to the right while driving and it was confirmed it not wheel allignment. I have decided to cancel the deal, sent a cancellation letter and now no one bothers to reply or answer my calls. Now thats what I call customer service. If We Buy Cars is so great as they advertise why not assist customers with issues? What must I do now.