Bad bad service from Bosch

I took my car to Bosch Service in Kempton Park last year February 2024, they charged me R6000 which I felt I was being bamboozled as a woman but I paid it anyway. It’s a Kia Rio and I have always taken to Kia for service until it ran out of a service plan. Fast forward to February 2025, the car was having a funny noise as I was driving, I took it to a credible mechanic and they found that the oil was as thick as petroleum Vaseline and no longer circulating properly throughout the engine, they had to open the engine tappet and clean it there and the oil pan. The mechanic was shocked that a car I claim was serviced last year at Bosch could have such bad oil and sludge, looks like they never even replaced the oil and filters nor was it cleaned. All of that had to be done today.